star trek stardate

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A chronometer in 2266

A stardate was a date in a variety of systems employed by the United Federation of Planets and other societies. It was usually expressed as a number of digits with a decimal separator, e.g. 5928.5 or 2263.02.

• 3.1.1 Gene Roddenberry: The Myth and the Man Behind Star Trek
• 3.1.2 The Star Trek Guide
• 3.1.3 The Making of Star Trek
• 3.1.4 Star Trek 30 Years Special Collector's Edition
• 3.1.5 The Next Generation era
• 3.1.6 Alternate reality
• 3.1.7 Star Trek: Discovery / Star Trek: Strange New Worlds
• 3.1.8 Star Trek: Picard
• 3.1.9 Deviations from production norms
• 3.1.10 Franz Joseph stardates
• 3.2.1 FASA reference stardates
• 3.4 External links

History [ ]

Classified Terran Empire records equated stardate 0141.7 to January 13, 2155

Stardate systems were used in certain cultures as early as the 2150s , when the United Earth government worked with calendar dates. In 2154 , Degra , a Xindi-Primate , sent a coded message to Enterprise NX-01 containing a stardate for when Enterprise should rendezvous with Degra's ship . T'Pol knew that it was three days in the future, indicating that Vulcans also had an understanding of stardates at that time. ( ENT : " Damage ") In the late 2250s, the Terran Empire used them to date events of 2155 . ( DIS : " Vaulting Ambition ")

By 2164 , Starfleet officers would open log entries with a stardate. By 2230 , the first four digits stood for the Gregorian calendar year. In the alternate reality of stardate 2258 , the Jellyfish gave its manufacturing date as "stardate 2387 ". ( Star Trek ) This scheme was used in the alternate reality as late as 2263 . ( Star Trek Beyond ) By 2256 in the prime reality , a more opaque relationship had been established between stardates and the Gregorian calendar. ( DIS : " The Vulcan Hello ") Variations on this scheme were used as late as 3188 . ( DIS : " People of Earth ")

Stardates did not replace clock time or everyday units for expressing larger timespans, such as days, weeks, months, years, centuries, or millennia, and stardate systems tend not to apply retroactively instead of Gregorian or Julian calendars either. ( TOS-R : " The Naked Time ")

Examples [ ]

The following table outlines the progress of stardates over time:

In an alternate timeline that diverged from the prime timeline in 2344 , the term combat date had replaced the term stardate in the dating system used by Starfleet by 2366 . The term was used during the Federation-Klingon War of that timeline . ( TNG : " Yesterday's Enterprise ")

Appendices [ ]

Background information [ ].

Stardates were first portrayed in TOS : " Where No Man Has Gone Before ", the second pilot for the series. Dave Eversole notes that the first draft of the teleplay (dated May 27, 1965) includes "Captain's Log, Report 197." [1] In addition, Star Trek Fact Check shows a scripted narration from the same draft containing "star date 1312.6". This became "star date 1312.4" by the final revised draft (July 8, 1965), which also asks for "C-1277.1 to 1313.7" to appear on Kirk's gravestone. According to Star Trek Fact Check , de Forest Research had this to say about stardates:

(Page 2, Scene 3) But on star date 1312.4 – Astronomers already have adopted a method of dating which makes possible the counting of the number of days elapsed between widely separated observations called 'the Julian Day'. Today July 14, 1965 is 2,438,956 in Julian days. A Julian cycle is 7,980 years, and the Julian day measurement would be scientifically authentic. Suggest "on Julian B 1312.4". This date would be August 5, 3271. (Page 65, Scene 175) C-1277.1 to 1313.7 – We presume dates are in days, Kirk would only be 36 days old. For conventional dating suggest 3235 to 3271. For Kirk's birth date in Julian system figure would be in millions. If desired, can be calculated.

On the other hand, the letter "C" and the rate of increase in the script suggest that 1277.1 was intended to be the date Kirk was promoted to captain and/or assumed command of the Enterprise , not his date of birth. Julian B is meant to be the day count since January 1, 3268, the start of the next 7,980-year Julian Period.

According to Kellam de Forest:

"The original script for the pilot of Star Trek was titled "Menagerie" (sic) and we in the research department, De Forest Research, didn't see it until it was in script form and came to us to review just like any other Desilu script, or any other script from any other client. So we got this script, and the script originally had dates in it, like 2362, and months and days. I felt that that sounded a little awkward for the 23rd, 22nd century, so I thought that there should be another, another dating system. So I checked that, yes, the astronomers had a way of dating called a Julian day system, in which, based on the calculations of a 16th century French mathematician/philosopher that felt that because he devised this calendar with a thousands and thousands of year cycle and each day was numbered, and astronomers have used that since, because it, you don't have to bother with years and leap years and AD and BC. So I suggested to Gene Roddenberry that there was this system out there and the days would be numbered, and he picked up on that and coined the term "stardate" and dated the log and the dating in Star Trek with this stardate system." [2]

Gene Roddenberry: The Myth and the Man Behind Star Trek [ ]

The second pilot was written by Samuel A. Peeples , who was interviewed by journalist Joel Engel for Gene Roddenberry: The Myth and the Man Behind Star Trek . [3] Replying to a newsgroup question on stardates, Engel quoted information from his book:

"For the starship captain's log entry narrations, Roddenberry wanted to devise a futuristic measurement of time reference. He called (Sam) Peeples (whom Roddenberry had contacted early on for help in learning about science fiction, a subject he knew nothing about; it was Peeples who wrote "Where No Man Has Gone Before," the pilot that sold ST). The two men had a few drinks while brainstorming, and soon began chuckling over their imaginative 'stardate' computations. 'We tried to set up a system that would be unidentified unless you knew how we did it,' Peeples says."

"They marked off sections on a pictorial depiction of the known universe and extrapolated how much earth time would elapse when traveling between given points, taking into account that the Enterprise's warp engines would be violating Einstein's theory that nothing could exceed the speed of light. They concluded that the 'time continuum' would therefore vary from place to place, and that earth time may actually be lost in travel. 'So the stardate on Earth would be one thing, but the stardate on Alpha Centauri would be different,' Peeples says. 'We thought this was hilarious, because everyone would say, "How come this date is before that date when this show is after that show?" The answer was because you were in a different sector of the universe.'" [4]

The Star Trek Guide [ ]

The following instructions to writers were copied from the series bible Star Trek Guide; they are quoted at Star Trek Fact Check . [5] The original date of composition and the author are unclear, but the sample stardates are consistent with the range from the second pilot.

"We invented "Stardate" to avoid continually mentioning Star Trek 's century (actually, about two hundred years from now), and getting into arguments about whether this or that would have developed by then. Pick any combination of four numbers plus a percentage point, use it as your story's stardate. For example, 1313.5 is twelve o'clock noon of one day and 1314.5 would be noon of the next day. Each percentage point (sic) is roughly equivalent to one-tenth of one day. The progression of stardates in your script should remain constant but don't worry about whether or not there is a progression from other scripts. Stardates are a mathematical formula which varies depending on location in the galaxy, velocity of travel, and other factors, can vary widely from episode to episode."

What is called a "percentage point" is actually the tenths digit. While the daily rate of increase wasn't always adhered to within episodes, the initial four digits weren't selected quite as randomly as described here. An overall increase with time can be observed in the above table of stardates, from 1312.4 in the second pilot to 5928.5 in the final episode of the series. The Animated Series and the movies continued the general trend, despite a number of variations in the rate of change.

The Making of Star Trek [ ]

Although much of the information from the Star Trek Guide was used in Stephen E. Whitfield 's book The Making of Star Trek (conceived in May 1967 and published in September 1968), the above specifics of selecting stardate numbers weren't included. However, the author did interview Gene Roddenberry on the subject, who provided a more elaborate rationalization for stardate behavior:

"In the beginning, I invented the term "star date" simply to keep from tying ourselves down to 2265 A.D., or should it be 2312 A.D.? I wanted us well into the future but without arguing approximately which century this or that would have been invented or superseded. When we began making episodes, we would use a star date such as 2317 one week, and then a week later when we made the next episode we would move the star date up to 2942, and so on. Unfortunately, however, the episodes are not aired in the same order in which we filmed them. So we began to get complaints from the viewers, asking, 'How come one week the star date is 2891, the next week it's 2337, and then the week after it's 3414?'"

"In answering these questions, I came up with the statement that "this time system adjusts for shifts in relative time which occur due to the vessel's speed and space warp capability. It has little relationship to Earth's time as we know it. One hour aboard the U.S.S. Enterprise at different times may equal as little as three Earth hours. The star dates specified in the log entry must be computed against the speed of the vessel, the space warp, and its position within our galaxy, in order to give a meaningful reading." Therefore star date would be one thing at one point in the galaxy and something else again at another point in the galaxy."

"I'm not quite sure what I meant by that explanation, but a lot of people have indicated it makes sense. If so, I've been lucky again, and I'd just as soon forget the whole thing before I'm asked any further questions about it."

Star Trek 30 Years Special Collector's Edition [ ]

Star Trek 30 Years Special Collector's Edition , published in 1996 by Paramount Pictures , states on page 81:

"Few Star Trek topics generate as much heated debate as the stardate system, the time calculation used by the United Federation of Planets which was introduced to the classic series by Gene Roddenberry, who borrowed the notion from the Julian date currently used by astronomers. Developed by Joseph Justus Scaliger (who named his dating system after his father, Julius Caesar Saliger), the Julian time calculation measures the number of days elapsed since 1 Jan. 4713 BC, the date derived by Joseph Justus. In the case of the 30th anniversary of the air date for the original series (8 Sept. 1996), that's 2,450,335 days. To make it easier, astronomers only use the last five digits – making 50335 the Julian date for the Star Trek anniversary. For Star Trek , Roddenberry added a single digit after the decimal point (50335.2) to represent one of the 10 time measurements in a 24-hour period… Roddenberry borrowed the five-digit Julian date, shortening it to four digits and renaming it "stardate"."

The Next Generation era [ ]

For the series that would come to be known as Star Trek: The Next Generation, Gene Roddenberry was intent on demystifying stardates, joking in his notes of May 14, 1986 that "In the original series, Stardates were determined by a complex formula based on the distance from Earth multiplied by the Producer’s birthday." The revised scheme would simply be a calendar date formatted YYY.MMDD, with the first season set in the year (2)487, the second in (2)488 and so forth, five hundred years into the future. To preserve order, the recommended day and the month would be the date of script assignment, to be replaced in the end by the date of shooting. (In a likely refinement, a typical summer-to-spring sequence of production dates would’ve required seasons to straddle two calendar years: 2487/88, 2488/89...) Anniversaries such as that of the lunar landing on stardate 487.0720 (pronounced "487 point oh-seven twenty") could then be celebrated by the crew. [6]

Ultimately, however, the teleplay of TNG : " Encounter at Farpoint " dated April 13, 1987 was assigned stardates ranging from 42353.7 to 42372.5. ( Star Trek: The Next Generation Companion CD ) This was changed to 41153.7-41174.2 on the air, consistent with the following description in Star Trek: The Next Generation Writer's/Director's Guide of March 23, 1987 (p. 13):

"A stardate is a five-digit number followed by a decimal point and one more digit. Example: "41254.7." The first two digits of the stardate are always "41." The 4 stands for 24th century, the 1 indicates first season. The additional three leading digits will progress unevenly during the course of the season from 000 to 999. The digit following the decimal point is generally regarded as a day counter."

As in TOS, stardates from the first season of TNG would sometimes decrease with time. In one noticeable example Tasha Yar 's death occurs around 41601.3 ( TNG : " Skin Of Evil "), but she was alive in episodes with greater stardates such as " The Big Goodbye ", set around stardate 41997.7.

The second season revision includes more detailed text regarding the decimal place, reiterating The Original Series rule:

"A Stardate is a five-digit number followed by a decimal point and one more digit. Example: "42254.7". The first two digits of the Stardate are always "42." The 4 stands for 24th Century, the 2 indicates second season. The additional three leading digits will progress unevenly during the course of the season from 000 to 999. The digit preceding the decimal point counts days , and the digit following the decimal point counts one-tenth of a day ." [7]

By the sixth season, "consecutively" had replaced "unevenly" from the above quote, consistent with the lack of decreasing stardates in later seasons of TNG.

"A Stardate is a five-digit number followed by a decimal point and one more digit. Example: "46254.7". The first two digits of the Stardate are "46." The 4 stands for the 24th Century, the 6 indicates sixth season. The following three digits will progress consecutively during the course of the season from 000 to 999. The digit following the decimal point counts tenths of a day . Stardate 45254.4, therefore, represents the noon hour on the 254th "day" of the fifth season. Because Stardates in the 24th Century are based on a complex mathematical formula, a precise correlation to Earth-based dating systems is not possible."

In actual fact, these thousand "days" would elapse in roughly a year, as demonstrated by numerous references in dialogue to events from previous seasons. The "century" digit was clarified as early as TNG : " Future Imperfect ", where the imaginary Jean-Luc Riker asks the computer to display his birthday party of stardate 58416, said to be less than sixteen years in the future of 2367. The initial digit may have been inspired by the 24th century, but in-universe it changes once a decade.

The writers of the Star Trek Chronology further developed the system by having a calendar year start at 000 and end at 999, although this does not fit all references in the show, such as a Diwali celebration around stardate 44390, too early in the year according to the simplified system. ( TNG : " Data's Day ") Stardate 41986.0 was in 2364 according to TNG : " The Neutral Zone ", hence the simplified system assumes that stardates 41xxx.x covered the entire year 2364, stardates 42xxx.x the entire year 2365 and so forth. As stated in Star Trek Chronology (p. 95):

"The year 2323 works out as the zero point for the system of stardates developed for Star Trek: The Next Generation , assuming that the beginning of year 2364 (the first season of Star Trek: The Next Generation ) was stardate 41000, and that stardates progress at 1000 units per year. In other words, under the Next Generation system of stardates, January 1, 2323 would seem to correspond to stardate 0. This probably shouldn't be taken too seriously, because Star Trek 's stardates have never been too internally consistent, but we're mentioning it here because it's kinda fun."

The second digit increased every season in TNG spin-offs as well. Since the contemporary DS9 premiered during the sixth season of TNG, stardates on the show ranged from 46379.1 to 52861.3. Likewise, the first season of Voyager (2371) would have paralleled the eighth season of TNG had it continued, so Voyager stardates ranged from 48315.6 to 54973.4. In at least one draft of the script, Star Trek Nemesis had a stardate of 47844.9, but the initial digits were changed to '56' for the film, consistent with Riker having been Picard's "trusted right arm for fifteen years." However, stardates of events prior to TNG : " Encounter at Farpoint ", but not so far back as the time of TOS, do not always conform to this method of counting. According to the Star Trek Chronology :

"Editors' confession: In "Dark Page" (TNG), an entry in Lwaxana's journal dated stardate 30620.1 is established to be during the year in which she got married, 2328. Unfortunately, under the Star Trek: The Next Generation system of stardates (which allocates 1,000 stardate units per year, and puts the beginning of year 2364 at stardate 41000) the beginning of the year 2328 should be around stardate 5000. Star Trek technical consultant (and Chronology co-author) Mike Okuda decided that a four-digit stardate would be confusing since this sounds like an Original Series number, so he arbitrarily picked 30620, even though it is not consistent with stardates used elsewhere in the show."

Okuda noted that in the Star Trek Chronology that there were "ambiguities" inherent in stardate calculation.

In addition to the overall rate of approximately one thousand units per year, many episodes confirm the 24-hour stardate unit mentioned in the series bibles. It is especially noticeable when the time of day is shown next to a stardate fraction, as demonstrated in the table below:

Although the vast majority of stardates are given with only one digit following the decimal point, the captain's log in TNG : " Code of Honor " is recorded with two digits (41235.25 and 41235.32) and other references have two, three, or even four digits, as in TNG : " The Child ", where a stardate of 42073.1435 is seen on a viewscreen in the Observation Lounge . Commenting on the graphic, Mike Okuda explained: " I always thought that the numbers after the decimal were fractions of a 24 hour day, meaning that .1435 would be about 3:20 in the morning. Which is really early in the day for a doctor's appointment... " [8] In VOY : " Relativity ", Seven of Nine travels back in time from 52861.274 to 49123.5621. Occasionally there are no digits, such as when "today's date" is given as stardate 47988. ( TNG : " All Good Things... ")

Alternate reality [ ]

The stardate format from the latest film series is credited to screenwriters Roberto Orci and Alex Kurtzman . According to Orci, they "used the system where, for example, 2233.45 or whatever means 23rd century, 33rd year of that century, and the .45 indicates the day of the year out of 365 days." [9] During a Q&A session, Orci restated that a stardate is "the year, as in 2233, with the month and day expressed as a decimal point from .1 to .365 (as in the 365 days of the year)." [10] He posted a similar reply on Twitter: "star date=standard year, with decimal representing day of year from 1-365." [11]

The new stardates are similar to the ordinal date s of ISO 8601, which would express the first day of 2260 as 2260-001, and the last as 2260-366. Orci hasn't clarified whether leap days increase the count to .366, which would be expected if the years are Gregorian. When asked about 2230.06 and 2233.04 from the Star Trek screenplay, with only one leading zero instead of two or none, he replied that it could have been an error. [12] IDW's Star Trek: Timelines show the latter number as 2233.4, while Star Trek Beyond places Kirk's birthday "a couple of days" after 2263.2 from his log entry. Shortly thereafter, Ambassador Spock's date of death is displayed as 2263.02, and his date of birth again as 2230.06. When Uhura calls for help from Krall's base, her screen shows "226X.XX", which isn't labeled a stardate but does suggest an entire two-digit range. Though farther from the films' production, the Star Trek Encyclopedia sees 2233.04 as January 4 of that year.

The alternate reality adaptation of " Where No Man Has Gone Before " begins with a stardate in the new style, but the second part of that comic reverts to 1313.1, consistent with the range of its prime reality counterpart, and the same approach is taken with " The Galileo Seven " reimagining, which begins on stardate 2821.5. After that story was finished, writer Mike Johnson commented at TrekMovie.com: " Speaking of typos... Going forward we are using the new Stardate system. " [13] Even so, not every alternate stardate may have been chosen correctly for the intended chronological order. According to Johnson in the Open Channels section of " The Q Gambit, Part 4 " (p. 25):

"The ongoing series is running in chronological order, except for those stories that are established as a flashback, like the origin of Science Officer 0718. So "The Q Gambit" takes place after "The Khitomer Conflict" and "Parallel Lives", and after the Enterprise has embarked on its new five-year mission after Star Trek Into Darkness ."

" The Q Gambit " begins on stardate 2261.34, and yet " The Khitomer Conflict " already saw the higher stardates 2261.147, .149 and .168. " Parallel Lives " continued with .274 and .234 in that order. " Live Evil, Part 1 " could not have been set after Star Trek Beyond , where the Enterprise is destroyed. Still, the digits after the separator always fall within Orci's range, even if the comics do not provide the matching days of the month. The table below shows only new-style stardates from the films and other sources, along with their calculated equivalents in the Gregorian calendar. Given the above evidence, the conversion provisionally assumes that .0# was always intended to mean Day #, not a fraction of the year.

As seen in the table, when asked by the alternate Spock , the computer aboard the Jellyfish reports a manufacturing stardate of 2387, consistent with the timespan of 129 years stated earlier in the film. The comic miniseries Star Trek: Countdown , which details events in the prime reality that led to the 2009 film , nevertheless gives its latest stardate as 64467.14, resulting in mid-2387 according to the Chronology rules. Moreover, Star Trek Online , set over twenty years after the destruction of Romulus, continues to use the format created for TNG, placing it in the 86000 range; on the other hand, Star Trek: Timelines freely applies alternate reality stardates to events from the prime reality.

Star Trek: Discovery / Star Trek: Strange New Worlds [ ]

A week before the premiere, the Star Trek Twitter page began counting up from 1200.4, continuing daily with 1201.5, 1202.4, 1203.4, 1204.5, 1205.4, 1206.5, and finally 1207.4, consistent with stardate 1207.3 of the first episode. [14] While this rate of increase matches the convention in TOS, the numbers are higher than 1024.7 for Joran Dax's birth in the following decade. Later episodes establish stardates in the actual TOS range, as well as the familiar changing rates and numbers decreasing with time. Having reached a peak in Season 1 of 4851.5, the initial digit reverts to 1 in Season 2, which ends with stardate 1201.7. Season 3 begins in the far future but preserves stardates as revised on TNG: 865xxx.x for the year 3188, though a number with eight integer digits and a decimal appears in an Emerald Chain document.

Star Trek: Picard [ ]

Writer, executive producer, and first season showrunner on Star Trek: Picard , Michael Chabon , eschewed the use of stardates, stating in an Instagram story dated 26 February 2020:

"Stardates, in my view, and I know this is going to make some people mad, are a uniquely perverse form of uninformative information. Using a stardate tells you precisely nothing. Even people who know how to interpret and convert them have to go off and interpret and convert them to have them mean something. Giving an audience the stardate is like I wanted to know if I needed to put on a sweater or not, and you told me the temperature outside in Kelvin. 'It's 287 out.'" [15]

The first stardate given was 78183.10 in the third season episode, “ No Win Scenario .” The second was 78186.03 in the next episode. In the series finale, " The Last Generation ,” William T. Riker says, “Captain’s log, stardate…shall we say, ‘One?’”

Deviations from production norms [ ]

Stardates would occasionally deviate from the prevailing production norm throughout Star Trek incarnations. Examples include:

• In TOS : " Where No Man Has Gone Before ", the stardates within the episode progress by 1.4, from 1312.4 to 1313.8, in what could not be more than a few days, yet the birthdates of Gary Mitchell and Elizabeth Dehner are given as 1087.7 (onscreen dossier age: 23) and 1089.5 (onscreen dossier age: 21), respectively. However, the numbers aren't explicitly labeled as stardates.
• The animated episode " The Magicks of Megas-Tu " set in 2269 has a stardate of 1254.4. This is lower than in any TOS episode, including the first Kirk-era show, TOS : " Where No Man Has Gone Before ", set in 2265 with a stardate of 1312.4.
• In Star Trek II: The Wrath of Khan , the opening graphic for Project Genesis is given a stardate of 7130.4, which should predate the USS Enterprise refit, yet Captain Kirk commented that the recording was just over a year old around stardate 8130.
• In TNG : " Datalore ", Riker dropped the fifth digit in his log, stating "stardate 4124.5". His entry is missing from the revised final draft of 10/26/87; it is surrounded by stardates 41242.4 and 41242.45, as recorded in Picard's log.
• In VOY : " Unimatrix Zero, Part II ", set during stardate 54014.4, Tuvok mentions that his date of birth is stardate 38774, but he was born in 2264.
• VOY : " Homestead " gives a stardate of 54868.6, which would suggest a date sometime in late 2377, but in fact the episode is set on the 315th anniversary of the first contact with Vulcans, which works out to April 5, 2378.

Franz Joseph stardates [ ]

Aside from those patterned after TOS, the stardates in the Star Fleet Technical Manual were generated using calendar dates of the 1970s, formatted YYMM.DD. This can be inferred by comparing the dates of first printing (November 1975) and of the 20th anniversary edition (September 1986) with the corresponding stardates, 7511.01 and 8609.01, as well as the decimal digits in technical order stardates, which suggest days of months. In addition to being easy to use, such stardates had the advantage of roughly matching in-universe ranges from the original film era. The 1979 Star Trek (Stardate) Calendar also used this format. [16]

Apocrypha [ ]

Fasa reference stardates [ ].

FASA 's Star Trek: The Role Playing Game released in the early 1980s used "reference stardates" ( β ) similar to those used by Franz Joseph. However, they prefixed a digit and a slash to represent the century, starting with the year 2000, so January 1, 2000, was 0/0001.01 and the Organian Peace Treaty was signed on 2/0801.24, or January 24, 2208 ( β ), according to Star Trek Spaceflight Chronology . Preceding centuries are negative, so the first episode of TOS aired -1/6609.08.

In the novel Where Sea Meets Sky , Captain Christopher Pike has to use conversion formulas to convert stardates to the Gregorian Calendar for his friend Nowan from the bar The Captain's Table.

In the Millennium novel The War of the Prophets , the stardate system is based on hyperdimensional distance averaging.

External links [ ]

• Stardate at Memory Beta , the wiki for licensed Star Trek works
• Universal Stardate Converter
• The Stardate FAQ – primarily develops one particular theory of stardates that has gained some currency
• Determining Calendar Dates from Stardates – has calculations and calculators based upon information from the television series' and movies
• Star Trek logs (X) – database of stardates and logs from the Star Trek films and television series
• Calendar conversion at Funaba.org – includes ordinal dates, which are practically identical to the alternate reality stardates

Screen Rant

Star trek: how stardates are calculated (& what they really mean).

The stardates used in the Star Trek franchise often seem like a jumble of numbers with no real meaning, but there is some method to the madness.

The stardate system used in the  Star Trek franchise can sometimes feel like a random selection of numbers, but there is some degree of meaning and calculation involved. When first devising and conceptualizing the futuristic world of  Star Trek , Gene Roddenberry decided that the advent of long-range space travel would necessitate a brand new way of measuring time, instead of the standard Gregorian calendar used in the real world. In 1988's  Inside Star Trek documentary, original series researcher, Kellam de Forest, revealed that he took inspiration from the 16th century Julian system, which has been implemented by astronomers ever since. Featuring a way of counting days, ignoring leap years and removing the AD and BC system, the Julian method formed the foundation for  Star Trek 's stardates.

The inspiration for the stardate system may have been simple enough, but applying it to the scripts proved far more complicated, and the exact correlation between  Star Trek  time and real-world time has changed throughout the various TV series and movie iterations. For the original  Star Trek series , the show's bible instructed writers to pick four numbers and a decimal, with the final digit roughly representing a tenth of a day. The example given is that if noon today was 1313.5, noon tomorrow would be 1314.5.

Related: The Odd-Numbered Star Trek Movie Curse Explained (& Is It True)

However, it's important to note that Roddenberry's initial system of dating was intentionally vague, with pilot episode writer, Samuel A. Peeples, revealing that the stardates weren't designed to be decipherable. Roddenberry was initially reluctant to pin  Star Trek  down to a specific time, so the stardate increments were uneven from episode to episode. Unfortunately,  Star Trek encountered a problem when the series first began to air - the network were showing the episodes out of order. This meant that while the stardates were originally supposed to increase as the series progressed, they actually fluctuated wildly. Roddenberry provided an in-narrative explanation for this phenomenon, claiming that stardates took into account the Enterprise 's speed and position in the galaxy, and therefore were relative to both space and time.

This somewhat clunky system was overhauled for  Star Trek: The Next Generation . As well as adding an extra digit,  The Next Generation 's writer's guide reveals that a more structured way of calculating stardates was implemented. The first number indicates the century (4 = 24th), the second number represents the season number (1 = season 1) and the following two digits would be largely random and vary with each episode, much like in the original  Star Trek series. The fifth digit functioned as a day counter, while, as in Roddenberry's original model, the decimal still represented a tenth of a day. This pattern was retained for both  Deep Space Nine and  Star Trek: Voyager .

When J. J. Abrams rebooted the  Star Trek movie series and splintered into the Kelvin timeline , a brand new dating system was introduced that bore a stronger resemblance to the real-world model. As revealed in the revised Star Trek Encyclopedia , the first two digits would represent century (22 = 23rd century), and the second two digits would calculate the year within that century. The 2009 movie also added more numbers after the decimal point, and these would indicate the day of the year. Therefore, 2235.78 would mean the 78th day of the 35th year of the 23rd century.

Beginning with  Star Trek: Discovery , CBS are now in the process of launching a whole new world of content set within the  Star Trek universe that will include  Star Trek: Picard and a Section 31 spinoff . Looking at the stardates used so far in Star Trek: Discovery , it appears that the franchise will come full circle, returning to the stardate system used in  Star Trek: The Original Series . However, with  Star Trek: Discovery  season 2 ending in the far future, the entire stardate system could become redundant when the show returns.

More: Star Trek: Discovery Makes A Bad Original Series Movie Better

Star Trek: Picard  is set to premiere in early 2020 on CBS All Access.

Sources:  Inside Star Trek ,  Gene Roddenberry: The Myth & The Man Behind Star Trek ,  The Making of Star Trek ,  Star Trek Encyclopedia

How Do Star Trek Stardates Work?

By chris higgins | sep 20, 2015.

On Star Trek , we hear a lot of "stardates," meant to mark some futuristic date. An example is stardate 47457.1, which is Captain Picard's birthday . The weird thing is that stardate 47457.1 is either the equivalent June 16th, November 4th, January 8th, or January 10th, depending on how you count. Let's go deep-nerd on this.

The Original Series

In the original Trek TV series, stardates were, in a word, bogus. In the series bible, the Star Trek Guide , writers were basically told to wing it. Here's a snippet (emphasis added):

Pick any combination of four numbers plus a percentage point [ed. note: tenths digit], use it as your story's stardate. For example, 1313.5 is twelve o'clock noon of one day and 1314.5 would be noon of the next day. Each percentage point is roughly equivalent to one-tenth of one day. The progression of stardates in your script should remain constant but don't worry about whether or not there is a progression from other scripts. Stardates are a mathematical formula which varies depending on location in the galaxy, velocity of travel, and other factors, can vary widely from episode to episode.

This obviously wasn't thought through very well, as it boils down to "Pick a number and stay near it." Show creator Gene Roddenberry later said:

When we began making episodes, we would use a stardate such as 2317 one week, and then a week later when we made the next episode we would move the star date up to 2942, and so on. Unfortunately, however, the episodes are not aired in the same order in which we filmed them. So we began to get complaints from the viewers, asking, "How come one week the star date is 2891, the next week it's 2337, and then the week after it's 3414?"

He then went on to explain that the whole "location in the galaxy, velocity of travel, and other factors" thing was a hedge to cover up the fact that the dates simply weren't consistent to begin with, even if the episodes had aired in order.

The Next Generation

In Star Trek: The Next Generation , things got a bit more consistent. In the original TNG Writer's/Director's Guide , the show-runners devised a sensible formula with a reasonable level of continuity. Here it is:

A stardate is a five-digit number followed by a decimal point and one more digit. Example: "41254.7." The first two digits of the stardate are always "41." The 4 stands for 24th century, the 1 indicates first season. The additional three leading digits will progress unevenly during the course of the season from 000 to 999. The digit following the decimal point is generally regarded as a day counter.

It's interesting to note, then, that the duration of a TNG season is 1,000 days. Good thing they were on a continuing mission rather than a five-year one.

Both Star Trek: Deep Space 9 and Star Trek: Voyager continued using the TNG style of Stardates, and the movie Star Trek Nemesis followed suit.

As you might expect, early on in TNG , the writers sometimes goofed. A prime example is Tasha Yar's death, which occurred circa Stardate 41601.3, but she was alive in a previous episode with the (later) Stardate 41997.7. Oops. By 1992, the writers had revised their guidelines to be iron-clad:

A Stardate is a five-digit number followed by a decimal point and one more digit. Example: "46254.7". The first two digits of the Stardate are "46." The 4 stands for the 24th Century, the 6 indicates sixth season. The following three digits will progress consecutively during the course of the season from 000 to 999. The digit following the decimal point counts tenths of a day. Stardate 45254.4, therefore, represents the noon hour on the 254th "day" of the fifth season. Because Stardates in the 24th Century are based on a complex mathematical formula, a precise correlation to Earth-based dating systems is not possible.

Despite explicitly stating that correlation to Earth-based dates is not possible, that hasn't stopped people from trying .

Just when things were basically making sense, they changed again. From an exhaustive and brilliant article on Memory Alpha , here's an explanation of the reboot (J.J. Abrams-directed) movies' treatment of stardates (emphasis added):

The stardate format from the latest film series is credited to screenwriters Roberto Orci and Alex Kurtzman. According to Orci, they "used the system where, for example, 2233.45 or whatever means 23rd century, 33rd year of that century, and the .45 indicates the day of the year out of 365 days." During a Q&A session, Orci restated that a stardate is "the year, as in 2233, with the month and day expressed as a decimal point from .1 to .365 (as in the 365 days of the year)." He posted a similar reply on Twitter: "star date=standard year, with decimal representing day of year from 1-365." The new stardates are similar to the ordinal dates of ISO 8601, which express the first day of 2260 as 2260-001, and the last as 2260-366. Orci hasn't clarified whether leap days increase the count to .366, which would be expected if the years are Gregorian. When asked about 2230.06 and 2233.04 from the Star Trek screenplay, with only one leading zero instead of two or none, he replied that it could have been an error. IDW's Star Trek: Timelines show the latter number as 2233.4.

Long Story Short

There is no one answer to how stardates work, aside from saying that they don't. They're inconsistent series-to-series, and even within a given series, the writers often mixed things up. With Roddenberry trying to retcon the system's continuity even in TOS , perhaps it's appropriate that the system continues to be more than a little mixed up. Time-tracking throughout the galaxy is a hard problem; give 'em some slack.

If you're curious about examples of various Stardates (and even more discussion of this issue), check out Memory Alpha 's stardate page . Trust me, once you've read that, you'll never want to speak of this subject again. If you do, read this page for a deeply unofficial (but supremely logical) system of decimal time. Oh, and don't forget the time the French made a 10-hour day —another attempt to create decimal time that led to total confusion.

Twenty-fourth Century Stardates

Calculating calendar dates in the next generation, deep space nine, and voyager.

While there have been very few references to actual dates in more than 700 episodes of Star Trek , it is possible to derive a fairly accurate correlation between the fictional Stardate system and calendar dates in The Next Generation , Deep Space Nine , and Voyager , based on facts from actual episodes and some calendar math . Facts: Fact: The Next Generation episode "The Neutral Zone," with a Stardate of 41986.0, gave the calendar year as 2364 at the end of the first season . Fact: The Next Generation episode "Data's Day" took place during the Hindu Festival of Lights . The episode aired the week of January 9, 1991 (two and a half years after "The Neutral Zone"), with a Stardate of 44390.1. Fact: Diwali , the five-day Festival of Lights, starts on the New Moon ending the month of Asvina on the Hindu calendar, which typically is the date of the New Moon in India nearest to Halloween. Fact: According to the Calendar Mine 2.0 perpetual calendar, November 3 is the date of the New Moon and the start of Diwali in the year 2366 on Earth. Therefore, the Hindu Festival of Lights would be celebrated in a five-day period starting on November 3, 2366, and ending on November 7, 2366, so Stardate 44390.1 must be within that date span. Fact: The Next Generation episode "Data's Day" also states that Stardate 44390.1 is the 1,550th day since the U.S.S. Enterprise was commissioned. Fact: In The Next Generation episode "All Good Things..." Picard states that he first met Q seven years before Stardate 47988. Their first meeting was depicted on Stardate 41153.7 in "ENCOUNTER AT FARPOINT." Fact: In the Voyager episode "EYE OF THE NEEDLE," Commander Chakotay states that the current year is 2371, with a Stardate of 48579.4. Fact: The Voyager episode "THE 37's" gave the calendar year as 2371 at the beginning of the second season, with a Stardate of 48975.1. Fact: In the Voyager episode "FUTURE'S END," information downloaded from the U.S.S. Voyager 's computer indicates that the Voyager was launched in the year 2371. The first episode of Voyager , "CARETAKER," took place on Stardate 48315.6. Fact: The date for the Voyager episode "11:59" was given as April 22, 2375. (No Stardate was given in the episode, but episodes airing before and after it had Stardates of 52647 and 52861.274.) Fact: The movie STAR TREK: FIRST CONTACT showed that humans made first contact with Vulcans on April 5, 2063. Fact: In the Voyager episode "HOMESTEAD," the crew is celebrating the 315th anniversary of First Contact Day. The following day, a captain's log is recorded on Stardate 54868.6. Fact: An average Earth year comprises about 365.2422 mean solar days. Calculations: Given the above facts, a consistent Stardate system must incorporate the following dates: Stardate 41986.0 must be in the year 2364 ("The Neutral Zone"). Stardate 44390.1 must be between November 3, 2366, and November 7, 2366 ( "Data's Day" ). Stardate 47988 takes place seven years after Stardate 41153.7 ( "ENCOUNTER AT FARPOINT," "All Good Things..." ). Stardate 48315.6 must be in the year 2371 ( "FUTURE'S END," "CARETAKER" ). Stardate 48579.4 must be in the year 2371 ( "EYE OF THE NEEDLE" ). Stardate 48975.1 must be in the year 2371 ( "THE 37's" ). April 22, 2375, takes place between Stardates 52647 and 52861.274 (assuming the episodes before and after "11:59" were in chronological order). Stardate 54868.6 is the day after First Contact Day, the 315th anniversary of April 5, 2063 ( "HOMESTEAD," ). Since The Next Generation episode "Data's Day" and the Voyager episode "HOMESTEAD" both make references to holidays with known dates, these two episodes can be used to establish a Stardate-to-time ratio. However, "Data's Day" (with a Stardate of 44390.1) could take place any time from November 3, 2366, to November 7, 2366, and it is unclear whether "HOMESTEAD" (with a Stardate 54868.6) takes place in the year 2378 or 2377, so that leaves a window of four possible calendar date spans for a definite span of 10478.5 Stardates. (54868.6 - 44390.1 = 10478.5 Stardates) If "Data's Day" took place on November 3, 2366, and "HOMESTEAD" took place on April 6, 2378, then that would give a span of 4,172 days. If "Data's Day" took place on November 7, 2366, and "HOMESTEAD" took place on April 6, 2378, then that would give a span of 4,168 days. If "Data's Day" took place on November 3, 2366, and "HOMESTEAD" took place on April 6, 2377, then that would give a span of 3,807 days. If "Data's Day" took place on November 7, 2366, and "HOMESTEAD" took place on April 6, 2377, then that would give a span of 3,803 days. Given the four possible date spans above, that leaves four possible Stardate-to-time ratios: 4,172 days = 10478.5 Stardates, giving a ratio of 0.39814859 day per Stardate, (4,172 days / 10478.5 Stardates = 0.39814859 day/Stardate) which gives a ratio of 917.351484 Stardates/year . (365.2422 days per year / 0.39814859 day per Stardate = 917.351484 Stardates/year) 4,168 days = 10478.5 Stardates, giving a ratio of 0.397766856 day per Stardate, (4,168 days / 10478.5 Stardates = 0.397766856 day/Stardate) which gives a ratio of 918.23186 Stardates/year . (365.2422 days per year / 0.397766856 day per Stardate = 918.23186 Stardates/year) 3,807 days = 10478.5 Stardates, giving a ratio of 0.36331536 day per Stardate, (3,807 days / 10478.5 Stardates = 0.36331536 day/Stardate) which gives a ratio of 1005.30349 Stardates/year . (365.2422 days per year / 0.36331536 day per Stardate = 1005.30349 Stardates/year) 3,803 days = 10478.5 Stardates, giving a ratio of 0.362933626 day per Stardate, (3,803 days / 10478.5 Stardates = 0.362933626 day/Stardate) which gives a ratio of 1006.36087 Stardates/year . (365.2422 days per year / 0.362933626 day per Stardate = 1006.36087 Stardates/year) If we apply each of the four possible Stardate ratios above to the known fact of the Voyager 's launch date in 2371, then we get the following results: Using the lowest possible Stardate-to-year ratio, 917.351484 Stardates/year , that would mean that the launch of the Voyager on Stardate 48315.6 ( "CARETAKER" ) would be 6553.0 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48315.6 = 6553.0) which would be 2,609.06771 days before April 6, 2378, (0.39814859 day per Stardate x 6553.0 Stardates = 2,609.06771 days) which would mean that "CARETAKER" took place on February 13, 2371. This fits with the fact that the Voyager was launched in 2371 ( "FUTURE'S END" ). Using the second-lowest possible Stardate-to-year ratio, 918.23186 Stardates/year , that would mean that the launch of the Voyager on Stardate 48315.6 ( "CARETAKER" ) would be 6553.0 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48315.6 = 6553.0) which would be 2,606.56621 days before April 6, 2378, (0.397766856 day per Stardate x 6553.0 Stardates = 2,606.56621 days) which would mean that "CARETAKER" took place on February 16, 2371. This fits with the fact that the Voyager was launched in 2371 ( "FUTURE'S END" ). Using the second-highest possible Stardate-to-year ratio, 1005.30349 Stardates/year , that would mean that the launch of the Voyager on Stardate 48315.6 ( "CARETAKER" ) would be 6553.0 Stardates before April 6, 2377 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48315.6 = 6553.0) which would be 2,380.80555 days before April 6, 2377, (0.36331536 day per Stardate x 6553.0 Stardates = 2,380.80555 days) which would mean that "CARETAKER" took place on September 30, 2370. This does not fit with the fact that the Voyager was launched in 2371 ( "FUTURE'S END" ). Using the highest possible Stardate-to-year ratio, 1006.36087 Stardates/year , that would mean that the launch of the Voyager on Stardate 48315.6 ( "CARETAKER" ) would be 6553.0 Stardates before April 6, 2377 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48315.6 = 6553.0) which would be 2,378.30405 days before April 6, 2377, (0.362933626 day per Stardate x 6553.0 Stardates = 2,378.30405 days) which would mean that "CARETAKER" took place on October 2, 2370. This does not fit with the fact that the Voyager was launched in 2371 ( "FUTURE'S END" ). Given the above results, we can discard possibilities 3 and 4, since they do not fit with a Voyager launch date of 2371. Since these were the only two options in which the episode "HOMESTEAD" took place in 2377, then we can conclude that "HOMESTEAD" must have taken place in April 2378, the 315th anniversary of first contact with Vulcans on April 5, 2063 ( STAR TREK: FIRST CONTACT ). (2063 + 315 = 2378) Having proven that "HOMESTEAD" must have taken place in April 2378, then that means that the only possible Stardate-to-year ratios are between 917.351484 Stardates/year and 918.23186 Stardates/year . If we apply each of these ratios to the fact that Stardate 48975.1 must be in the year 2371 ( "THE 37's" ), we get the following results: Using the lowest possible Stardate-to-year ratio, 917.351484 Stardates/year , that would mean that "THE 37's" (on Stardate 48975.1) would be 5893.5 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48975.1 = 5893.5) which would be 2,346.48872 days before April 6, 2378, (0.39814859 day per Stardate x 5893.5 Stardates = 2,346.48872 days) which would mean that "THE 37's" took place on November 3, 2371. This fits with the stated year of 2371 in "THE 37's" . Using the highest possible Stardate-to-year ratio, 918.23186 Stardates/year , that would mean that "THE 37's" (on Stardate 48975.1) would be 5893.5 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 48975.1 = 5893.5) which would be 2,344.23897 days before April 6, 2378, (0.397766856 day per Stardate x 5893.5 Stardates = 2,344.23897 days) which would mean that "THE 37's" took place on November 5, 2371. This fits with the stated year of 2371 in "THE 37's" . If we apply each of the above ratios to the fact that Stardate 41986.0 must be in the year 2364 ("The Neutral Zone"), we get the following results: Using the lowest possible Stardate-to-year ratio, 917.351484 Stardates/year , that would mean that TNG episode "The Neutral Zone" (on Stardate 41986.0) would be 12882.6 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 41986.0 = 12882.6) which would be 5,129.18903 days before April 6, 2378, (0.39814859 day per Stardate x 12882.6 Stardates = 5,129.18903 days) which would mean that "The Neutral Zone" took place on March 21, 2364. This fits with the stated year of 2364 in "The Neutral Zone." Using the highest possible Stardate-to-year ratio, 918.23186 Stardates/year ,that would mean that TNG episode "The Neutral Zone" (on Stardate 41986.0) would be 12882.6 Stardates before April 6, 2378 ( "HOMESTEAD" ), which had a Stardate of 54868.6, (54868.6 - 41986.0 = 12882.6) which would be 5,124.2713 days before April 6, 2378, (0.397766856 day per Stardate x 12882.6 Stardates = 5,124.2713 days) which would mean that "The Neutral Zone" took place on March 26, 2364. This fits with the stated year of 2364 in "The Neutral Zone." Conclusions: Given the above facts and calculations , we can conclude that: The Voyager episode "HOMESTEAD" (Stardate 54868.6) must have taken place on April 6, 2378. The highest possible Stardate-to-year ratio is 918.23186 Stardates per year (or 0.397766856 day to 1.0 Stardate , or 1.0 Stardate to 34,367.0564 seconds ). With the two above conclusions, it is possible to calculate a calendar date for any Stardate given in The Next Generation , Deep Space Nine , and Voyager . Given the date of Voyager episode "HOMESTEAD" (Stardate 54868.6) and a ratio of 918.23186 Stardates per year, it is now possible to calculate the starting point of The Next Generation Stardate system, i.e., Stardate 00000.0. Stardate 00000.0 would be 54868.6 Stardates before April 6, 2378 ( "HOMESTEAD" ), which, given the Stardate-to-year ratio established above, would be 21,824.9105 days before April 6, 2378. (0.397766856 day/Stardate x 54868.6 Stardates = 21,824.9105 days) Subtracting 21,824 days, 1,311 minutes, from April 6, 2378, calculates to Friday, July 5, 2318, around noon. So we can conclude that Stardate 00000.0 started on Friday, July 5, 2318 , around noon (Starfleet Command time).

Twenty-third Century Stardates

Calculating calendar dates in the original series.

During the run of The Original Series , there were few references to dates, nor even to the century in which the series took place. Furthermore, the Stardates used in The Original Series had a different starting point than The Next Generation Stardates, so it is impossible to directly extrapolate dates backwards from The Next Generation . However, there were sufficient references in The Next Generation to retroactively calculate dates in The Original Series , with a few additional Stardate facts from episodes of The Original Series , The Next Generation , and Voyager . Facts: Fact: In The Next Generation episode "Sarek," Captain Picard states that Ambassador Sarek is 202 years old. The episode takes place on Stardate 43917.4, which, according to the above calculations , would take place on Tuesday, May 3, 2366. Thus, for Picard's statement to be true on that date, Sarek would have been born between May 4, 2163 and May 3, 2164. Fact: In The Original Series episode "JOURNEY TO BABEL," Ambassador Sarek states that he is precisely 102.437 Earth years old on Stardate 3842.4. Based on the above range determined for the date of Sarek's birth, "JOURNEY TO BABEL" must have taken place between October 11, 2265, and October 9, 2266. Fact: The American Thanksgiving holiday typically is celebrated on the fourth Thursday of November. Fact: In The Original Series episode "CHARLIE X," the crew of the U.S.S. Enterprise is celebrating Thanksgiving. The given Stardates for this episode were 1533.6 and 1533.7. This is 2308.7 Stardates before Stardate 3842.4 in the episode "JOURNEY TO BABEL," which was determined above to have taken place between October 11, 2265, and October 9, 2266. (3842.4 - 1533.7 = 2308.7 Stardates) Fact: Captain Kirk's monologue in the opening titles of The Original Series established that the crew was on a five-year mission. The earliest Stardate in The Original Series was 1312.4 in "WHERE NO MAN HAS GONE BEFORE," and the latest Stardate was 5943.7 in "ALL OUR YESTERDAYS," a difference of 4631.3 Stardates. (5943.7 - 1312.4 = 4631.3 Stardates) Fact: If episodes of The Animated Series are also considered part of the original five-year mission, then the earliest Stardate was 1254.4 in the animated episode "THE MAGICKS OF MEGAS-TU," and the latest Stardate was 7403.6 in the animated episode "BEM," a difference of 6149.2 Stardates. (7403.6 - 1254.4 = 6149.2 Stardates) Fact: In the Voyager episode "Q2," Icheb states that Kirk completed his historic five-year mission in 2270. Therefore, all episodes of The Original Series must have taken place after January 1, 2265 (assuming it was exactly five years), and before January 1, 2271. Fact: In the episode "DAGGER OF THE MIND," on Stardate 2715.1, Dr. Helen Noel said she met Captain Kirk at the Science Lab Christmas party. Fact: Christmas is traditionally celebrated on December 25, and office Christmas parties are typically celebrated sometime in December. Given the possible date range for the five-year mission established in "Q2," the Christmas party referred to in "DAGGER OF THE MIND" must have taken place between December 2265 and December 2270. Calculations: Thanksgiving in "CHARLIE X" took place before the episode "JOURNEY TO BABEL" -- which, as determined above, took place between October 11, 2265, and October 9, 2266 -- and Thanksgiving in "CHARLIE X" must have taken place after January 1, 2265, given the end date of the five-year mission in "Q2." Therefore, the only possible date for "CHARLIE X" would be November 23, 2265 (which is the fourth Thursday of the month, according to the perpetual calendar ). If the Christmas party referred to in "DAGGER OF THE MIND" is assumed to be the same year as Thanksgiving in "CHARLIE X," then there would be at least a month between the two episodes, a difference of 1181.4 Stardates (giving a ratio of less than 1,000 Stardates per month). If the Christmas party were the following year, then the difference of 1181.4 Stardates would span at least a year (which would give a ratio of at least 1,000 Stardates per year). The Christmas party referred to could not be from the year before Thanksgiving in "CHARLIE X," since the possible date range for the five-year mission established in "Q2" dictates that the five-year mission did not begin before 2265. Having calculated above that Stardate 1533.7 is on November 23, 2265 ( "CHARLIE X," ), and that Stardate 3842.4 ( "JOURNEY TO BABEL" ) must be between October 11, 2265, and October 9, 2266, the maximum span between Stardates 1533.7 and 3842.4 (a difference of 2308.7 Stardates) can be no more than 320 days (or 0.876130962 year). Therefore, there must be at least 2635.10833 Stardates per year (or at least 7.21468749 Stardates per day). (2308.7 Stardates / 0.876130962 year = 2635.10833 Stardates/year) This means that Stardate 0000.0 -- 1533.7 Stardates before November 23, 2265, in "CHARLIE X" -- must have started 0.582025408 year (212.58024 days) before that episode. (1533.7 Stardates / 2635.10833 Stardates/year = 0.582025408 year) So, assuming the lowest possible Stardate-to-year ratio of 2635.10833 Stardates per year, Stardate 0000.0 began on Tuesday, April 25, 2265, at 00:00 hours. (November 23, 2265 - 212.58024 days = April 25, 2265) Conclusions: Given the above facts and calculations , we can conclude that: Stardate 0000.0 began on Tuesday, April 25, 2265, at 00:00 hours. The lowest possible Stardate-to-year ratio is 2635.10833 Stardates per year (at least 7.21468749 Stardates per day , or less than 0.138606142 day per Stardate ). Therefore, in The Original Series , one Stardate is no more than 11,975,570.7 milliseconds (0.138606142 day = 11,975,570.7 milliseconds) Given the above starting point and the assumed ratio of 2635.10833 Stardates per year, it is possible to calculate the calendar date for any episode in The Original Series . For example, "DAGGER OF THE MIND," on Stardate 2715.1, would have taken place on May 6, 2266, just a few months after the Christmas party referred to in the episode. So the earliest Stardate in The Original Series -- 1312.4 in "WHERE NO MAN HAS GONE BEFORE" -- took place on October 23, 2265, and the latest Stardate -- 5943.7 in "ALL OUR YESTERDAYS" -- was on July 27, 2267. (The earliest Stardate in The Animated Series -- 1254.4 in "THE MAGICKS OF MEGAS-TU" -- would have taken place on October 15, 2265, and the latest Stardate -- 7403.6 in "BEM" -- would have taken place on February 15, 2268.)

Late Twenty-third Century Stardates

Calculating calendar dates in the movie series.

The first six Star Trek motion pictures continued the pattern of four-digit Stardates from The Original Series . However, it is clear that it is not a simple linear continuation of the same Stardate system. Therefore, either the time ratio of The Original Series Stardates changed mid-way through the original five-year mission and continued through the movies, or else the motion pictures use another Stardate system with a completely new starting point and different time ratio from The Original Series Stardates. Facts: Fact: In STAR TREK: THE MOTION PICTURE , on Stardate 7410.2, Admiral James Kirk has been Chief of Starfleet Operations for the past two and a half years, and hasn't logged a single star hour in that time, since completing his five-year mission. So, based on the end date of the five-year mission established in "Q2," Stardate 7410.2 must be at least two and a half years after January 1, 2270. Fact: Since STAR TREK: THE MOTION PICTURE , on Stardate 7410.2, takes place two and a half years after Captain Kirk's original five-year mission ended, then it must be at least two and a half years after the latest Stardate in The Original Series -- 5943.7 in "ALL OUR YESTERDAYS" -- a difference of 1466.5 Stardates. (7410.2 - 5943.7 = 1466.5 Stardates) Fact: If episodes of The Animated Series are also considered part of the original five-year mission, then STAR TREK: THE MOTION PICTURE , on Stardate 7410.2, must take place at least two and a half years after the latest Stardate -- 7403.6 in the animated episode "BEM" -- a difference of 0006.6 Stardates. (7410.2 - 7403.6 = 0006.6 Stardates) Fact: In STAR TREK: THE MOTION PICTURE , on Stardate 7410.2, V'ger is less than three days away from Earth. On Stardate 7414.1, V'ger reaches Earth, so a span of 0003.9 Stardates must be less than three days. (7414.1 - 7410.2 = 0003.9 Stardates) Fact: In STAR TREK II: THE WRATH OF KHAN , the Project Genesis video proposal was recorded by Dr. Carol Marcus on Stardate 7130.4. After Stardate 8130.4, Admiral Kirk states that the tape was made "about a year ago." Fact: In STAR TREK II: THE WRATH OF KHAN , on Stardate 8130.4, Khan has been stranded on Ceti Alpha Five for 15 years, since Stardate 3143.3 in the episode "SPACE SEED" -- which, according to The Original Series Stardate calculations above, would have taken place on July 4, 2266. Therefore, Stardate 8130.4 must take place after July 4, 2281 (assuming Khan is talking about Earth years and not Ceti Alpha Five years). Fact: In STAR TREK II: THE WRATH OF KHAN , on Stardate 8130.3, Dr. McCoy gives Admiral Kirk a bottle of Romulan Ale (vintage 2283) for his birthday. Therefore, Stardate 8130.3 must take place after 2283 (assuming 2283 is an Earth year, and not a Romulan year or a Stardate). Fact: In STAR TREK III: THE SEARCH FOR SPOCK , around Stardate 8210.3, Starfleet Commander Morrow states that the U.S.S. Enterprise is twenty years old. An officer later refers to Uhura as a twenty-year space veteran. Fact: In STAR TREK III: THE SEARCH FOR SPOCK , the U.S.S. Enterprise flight recorder shows that Spock was dying from radiation poisoning after escaping the Genesis Device detonation on Stardate 8128.78. On Stardate 8128.77, Spock had just been exposed to radiation. Stardates 8128.76.00 to 8128.76.32 spanned a few seconds in which Spock performed a mind-meld with Dr. McCoy before entering the irradiated Engineering chamber. Fact: In STAR TREK IV: THE VOYAGE HOME , on Stardate 8390, the U.S.S. Enterprise crew has been on Vulcan for three months (since just after Stardate 8210.3 in STAR TREK III: THE SEARCH FOR SPOCK ). Therefore, a span of 179.7 Stardates represents at least three months (8390 - 8210.3 = 179.7 Stardates) , so 718.8 Stardates would span at least 12 months (179.7 Stardates/3 months x 4/4 = 718.8 Stardates/12 months) . Fact: In STAR TREK V: THE FINAL FRONTIER , on Stardate 8454.1, the U.S.S. Enterprise NCC-1701-A has been under repairs for at least three weeks. The starship was first seen sometime after Stardate 8390 in STAR TREK IV: THE VOYAGE HOME , so there must be at least a month in the span of 64.1 Stardates (8454.1 - 8390 = 64.1 Stardates) ; therefore, there must be at least a year in a span of 769.2 Stardates (64.1 Stardates x 12 = 769.2 Stardates) . Fact: In STAR TREK VI: The Undiscovered Country , on Stardate 9521.6, the U.S.S. Excelsior detected the destruction of the Klingon moon Praxis, three years after Captain Sulu took command. Two months later, Starfleet Command sends the U.S.S. Enterprise on a diplomatic mission, and Captain Kirk records a log entry on Stardate 9522.6. A few days later, Captain Kirk records his final log entry on Stardate 9529.1. Therefore, a span of 1.0 Stardate is at least two months. (9522.6 - 9521.6 = 1.0 Stardate) . Fact: In STAR TREK VI: The Undiscovered Country , after Stardate 9522.6, McCoy states that he has been ship's surgeon aboard the U.S.S. Enterprise for 27 years. Fact: In the Voyager episode "FLASHBACK," after Stardate 50126.4, Tuvok states that his first deep space assignment aboard the U.S.S. Excelsior , on Stardate 9521, was approximately 80 years ago, when he was 29 years old. Given the assumed date of Tuvok's birth on October 14, 2266, then Stardate 9521 must be at least 29 years after October 14, 2266. However, this conflicts with McCoy's statement that he has been aboard the U.S.S. Enterprise for only 27 years, since his earliest appearance, on Stardate 1512.2 in "THE CORBOMITE MANEUVER," was almost a year before Tuvok's birth .

Star Trek XI-XII Stardates

Calculating calendar dates in the latest movie.

Fact: In STAR TREK , on Stardate 2258.42, Ambassador Spock states that Stardate 2387 is about 129 years in the future, and Stardate 2233.04 is about 25 years in the past. (2387 - 2258.42 = 128.58 Stardates) , (2258.42 - 2233.04 = 25.38 Stardates) . Fact: An average Earth year comprises about 365.2422 mean solar days. Therefore, each 100th of a year would be 3.652422 days. (1 year / 100 = 365.2422 days / 100 = 3.652422 days) . Fact: In STAR TREK INTO DARKNESS , Stardate 2259.55 is approximately one year later than the events in the previous movie (whose Stardate was 2258.42). . Conclusion: The new STAR TREK film appears to use a ratio of one Stardate per year; more specifically, the Stardates in the film are consistent with the actual Earth calendar years expressed with two decimal places (presumably representing hundredths of the calendar year). These new Stardates are used to express calendar dates both before The Original Series Stardates and after The Next Generation Stardates . Using this information, and the above TNG Stardate Calculator and TOS Stardate Calculator , these new Stardates can be compared with calendar dates from both The Original Series and The Next Generation . For example, Ambassador Spock's given Stardate of 2387 in STAR TREK would take place about eight years after the latest known TNG Stardate in STAR TREK: NEMESIS , whose given Stardate of 56844.9 would be around March 29, 2379, according to the above TNG Stardate Calculator . Also, the given Stardate of 2258.42 in STAR TREK , when James Kirk is around 25 years old, would take place about seven years before the earliest Stardate in The Original Series , 1312.4 in "WHERE NO MAN HAS GONE BEFORE," which would be around October 24, 2265, according to the above TOS Stardate Calculator . Kirk's birth on Stardate 2233.04 depicted in STAR TREK would be around January 15, 2233 , assuming Stardate 2233.00 corresponds with 00:00 hours on January 1, 2233. (00:00 January 1, 2233 + 0.04 x 365.2422 days = 00:00 January 1, 2233 + 14.609688 days) . Given Kirk's birth date of January 15, 2233 (assuming his birth date in the alternate universe depicted in STAR TREK was the same as, or close to, his birth date in The Original Series ), his exact age can now be calculated for any Stardate given in an episode of The Original Series . In addition, in STAR TREK II: THE WRATH OF KHAN , Admiral Kirk is celebrating his birthday on Stardate 8130.3 when Dr. McCoy gives him a bottle of Romulan Ale (vintage 2283). Therefore, Stardate 8130.3 (in The Movie Series Stardate system ) must take place around January 15 in some year after 2283 (or a few weeks after January 15, if it is assumed that the alternate events depicted in STAR TREK caused Kirk to be born prematurely).

Date inconsistencies in episodes

While the episodes and assumptions cited above present a fairly accurate and consistent theory for calculating Stardates, there are many other date references -- mostly vague references to years -- that conflict with that theory, though these exceptions do not clearly establish a more-consistent alternative theory, so they may be regarded as errors. Stardate-to-year ratios: In The Original Series episode "THE CORBOMITE MANEUVER" , the span between Stardate 1512.2 and Stardate 1513.8 is described as "18 hours." That is a difference of 1.6 Stardate units (1513.8 - 1512.2 = 1.6 Stardates) . If 1.6 Stardates are 18 hours, then 1 Stardate would equal 11.25 hours (18 hours / 1.6 Stardates = 11.25 hours/Stardate) , and 2.13333333333 Stardates would be one day (24 hours/day / 11.25 hours/Stardate = 2.13333333333 Stardates/day) , so 779.18336 Stardates would be about a year (2.13333333333 Stardates/day x 365.2422 days/year = 779.18336 Stardates/year) . Given the above calculations that there must be at least 2635.10833 Stardates per year (or at least 7.21468749 Stardates per day), the Stardates and hours stated in "THE CORBOMITE MANEUVER" are inconsistent with the overall progression of Stardates in The Original Series . In The Original Series episode "THE GAMESTERS OF TRISKELION" , the span between Stardate 3211.8 and Stardate 3259.2 is described as "nearly two hours." That is a difference of 47.4 Stardate units (3259.2 - 3211.8 = 47.4 Stardates) . If 47.4 Stardates are nearly two hours, then 568.8 Stardates would be nearly a day (47.4 Stardates/2 hours x 24 hours/day = 568.8 Stardates/day ) , and 207,749.76 Stardates would be nearly a year (568.8 Stardates/day x 365.2422 days/year = 207749.76 Stardates/year) . This is inconsistent with the slow progression of four-digit Stardates throughout The Original Series , demonstrating that Stardate spans shown within single episodes cannot be extrapolated to measure Stardates across multiple episodes. In The Next Generation episode " Pen Pals ," the Enterprise enters the Selcundi Drema Sector on Stardate 42695.3. On Stardate 42696.3, Lieutenant Commander Data picks up an alien radio signal. On Stardate 42737.3, Captain Picard states that it has been six weeks since the Enterprise entered the Selcundi Drema Sector. Shortly before Stardate 42741.3, Data says he picked up the alien transmission eight weeks ago. So there is a span of 42.0 Stardates in six weeks (42737.3 - 42695.3 = 42.0 Stardates) , for a ratio of about 7.0 Stardates per week, and a span of 45.0 Stardates in at least eight weeks (42741.3 - 42696.3 = 45.0 Stardates) , for a ratio of 5.625 Stardates per week. These ratios would extrapolate to about 1 Stardate per day, or between 292 and 365 Stardates per year . In The Next Generation episode "The Best of Both Worlds" Part II ," the battle between Starfleet and the Borg at Wolf 359 starts after Stardate 44001.4. and shortly before Stardate 44002.3. In the Deep Space Nine episode "EMISSARY," it was stated that Captain Picard was kidnapped by the Borg on Stardate 43997 for six days, during which he led an assault on Starfleet at Wolf 359, resulting in the death of Jennifer Sisko. Three years later, on Stardate 46379.1, Commander Sisko is reassigned to station Deep Space Nine in orbit of Bajor. So there is a span of about 2376.8 Stardates in three years (46379.1 - 44002.3 = 2376.8 Stardates) , for a ratio of about 792.266666667 Stardates per year (2376.8 Stardates / 3 years = 792.266666667 Stardates/year) . In the Deep Space Nine episode "SECOND SIGHT," on Stardate 47329.4, Commander Sisko records a personal log stating that the previous day was the fourth anniversary of the massacre at Wolf 359 and the death of Jennifer Sisko. So there is a span of about 3327.1 Stardates in four years (47329.4 - 44002.3 = 3327.1 Stardates) , for a ratio of about 831.775 Stardates per year (3327.1 Stardates / 4 years = 831.775 Stardates/year) . (It is unclear whether Sisko is describing Earth years or Bajoran years, since he is on a Bajoran station with 26 hours per day.) In the Voyager episode "RELATIVITY" , Seven of Nine states on Stardate 49123.5621 that the Voyager will be destroyed in three years, six months and two days, on Stardate 52861.274 -- a difference of 3737.7119 Stardates. This is a span of 1,280 to 1,282 days (3.504522888 to 3.509998705 years), depending on leap years and lengths of different months, giving a ratio of around 1,065 Stardates per year . In the Voyager episode "TIMELESS," Captain Janeway states that the Voyager has been in the Delta Quadrant for four years, two months, and 11 days. The following morning, around 08:00 hours, she records a log entry on Stardate 52143.6. In the Voyager episode "CARETAKER," the Voyager was brought to the Delta Quadrant three days before Stardate 48315.6 -- a difference of 3828.0 Stardates before "TIMELESS." Therefore, there is a span of 1,531 days (4.191737923 years) in a span of 3828.0 Stardates, giving a ratio of 913.225 Stardates per year . Between Day 65 and Day 70 of the Voyager episode "YEAR OF HELL," a captain's log was recorded on Stardate 51268.4 (May 5, 2374, according to the above calculations ), and Chakotay later mentions that it is May 20 (Captain Janeway's birthday). In "YEAR OF HELL, PART II," on Day 133 a captain's log is recorded on Stardate 51425.4 (July 6, 2374, according to the above calculations ). Between Day 207 and Day 257, Janeway mentions her birthday was "five months ago;" she later records a captain's log on Stardate 51682.2 (October 16, 2374, according to the above calculations ). On Day 1 after the timeline is restored, a captain's log is recorded on Stardate 51252.3 (April 28, 2374, according to the above calculations ). Therefore, there is a span of 16.1 Stardates in the first 64 days of the "YEAR OF HELL" (51268.4 - 51252.3 = 16.1 Stardates) , giving a ratio of 0.2515625 Stardate per day (16.1 Stardates / 64 days = 0.2515625 Stardate/day) , or 91.88 Stardates per year . The captain's log recorded between Day 207 and Day 257 would be 429.9 Stardates after Day 1 (51682.2 - 51252.3 = 429.9 Stardates) and at least "five months" or 413.8 Stardates after Day 65 (51682.2 - 51268.4 = 413.8 Stardates) . These date spans give a possible ratio of around 700 to 1,000 Stardates per year . The captain's log recorded on Stardate 51425.4 on Day 133 would be 173.1 Stardates after Stardate 51252.3 on Day 1 (51425.4 - 51252.3 = 173.1 Stardates) , giving a span of 173.1 Stardates in 132 days, or a ratio of 1.3113636364 Stardates per day (173.1 Stardates / 132 days = 1.3113636364 Stardates/day) , or 478.96533956 Stardates per year . In The Next Generation episode "The Naked Now," Data first uses his sexual techniques just after Stardate 41209.3 (May 22, 2363, according to the above calculations ). In STAR TREK: FIRST CONTACT , a couple days after Stardate 50893.5 (December 7, 2373, according to the above calculations ), Data states that he last used his programming in sexual techniques eight years, seven months, sixteen days, four minutes, twenty-two seconds ago (which, according to the date calculator , would be a couple days after April 21, 2365, or after Stardate 42973, according to the above calculations ; this would place Data's last use of his programming in sexual techniques between the last two episodes in The Next Generation 's second season ). However, if Data used his programming in sexual techniques only twice -- in "The Naked Now" and STAR TREK: FIRST CONTACT -- then the span of "eight years, seven months, sixteen days, four minutes, twenty-two seconds" (or 272,333,062 seconds) would be a little more than the span between Stardates 41209.3 and 50893.5 (9684.2 Stardates), giving a ratio of less than 9684.2 Stardates per 272,333,062 seconds (or 8.62989831 years), or less than 1122.16849517 Stardates per year . ( 9684.2 Stardates / 8.62989831 years = 1122.16849517 Stardates/year) (50893.5 - 41209.3 = 9684.2 Stardates) . That gives a ratio of more than 1122.5 Stardates per year (9684.2 Stardates / 8.6274 years = 1122.5 Stardates/year) . From and including: Wednesday, April 21, 2365 at 4:52:02 AM To, but not including : Friday, December 7, 2373 at 4:56:24 AM The duration is 3152 days, 0 hours, 4 minutes and 22 seconds Or 8 years, 7 months, 16 days, 4 minutes, 22 seconds Alternative time units 3152 days, 0 hours, 4 minutes and 22 seconds can be converted to one of these units: 272,333,062 seconds 4,538,884 minutes (rounded down) 75,648 hours (rounded down) 450 weeks (rounded down) From date: Friday, December 7, 2373 at 4:56:24 AM Subtracted 8 years, 7 months, 16 days, 4 minutes, 22 seconds Resulting date: Wednesday, April 21, 2365 at 4:52:02 AM (last used) May 22 2363 (first used) --> Given the wild inconsistencies of Stardate ratios in different episodes, some varying by a factor of ten, there can be no conclusive determination of an actual Stardate-to-year ratio for all episodes. Therefore, the ratio of 918.23186 Stardates per year , as calculated above , will remain the basic assumption upon which the above TNG Stardate Calculator is based. Tuvok's Birthday In the Voyager episode "EX POST FACTO," it is stated that Tuvok has been married for 67 years. In the Voyager episode "FLASHBACK," after Stardate 50126.4, Tuvok states that his first deep space assignment aboard the U.S.S. Excelsior , on Stardate 9521, was approximately 80 years ago, when he was 29 years old. In the episode "UNIMATRIX ZERO" PART II , it is stated that Tuvok was born on Vulcanis Lunar Colony on Stardate 38774. This last reference is clearly an error, since Stardate 38774 in The Next Generation system would be just three years before "The Neutral Zone" (41986.0), which gave the year as 2364 -- meaning Tuvok would be just 10 years old in Voyager 's first episode on Stardate 48315.6. It is likely that the decimal was left out of Tuvok's given birth date, and he was really born on Stardate 3877.4 (October 14, 2266, based on the above calculations ) in The Original Series Stardate system. This would place his birth just after The Original Series episode "JOURNEY TO BABEL" , which had a Stardate of 3842.3. Given a birth date of October 14, 2266, Tuvok would be about 106 years old on Stardate 50126.4 in "FLASHBACK," which would be on February 5, 2373, according to the above Stardate Calculator . As stated in "FLASHBACK," Tuvok was 29 years old on Stardate 9521, meaning that STAR TREK VI: The Undiscovered Country must have taken place within the year following October 14, 2295. However, in the episode "FURY," Captain Janeway celebrates Tuvok's birthday, stating it is not long before he reaches "the big three digits." The episode had no Stardate, but the episode before it took place on Stardate 53918, which would place it in the middle of 2377 (based on the above calculations ). If the statement "the big three digits" is taken to mean "100 Earth years," then this would mean that Tuvok would be born after 2277, making him 11 years younger than assumed above. But if "the big three digits" is taken to mean "111 Earth years" (three identical digits), that would be consistent with the above assumptions, since Tuvok would be born on October 14, 2266 (TOS Stardate 3877.4), making him 111 years old on October 14, 2377. This could mean that "FURY," (which had no Stardate) might be shown out of order, and actually took place on Tuvok's 110th birthday, October 14, 2376. (Of course, it is unclear whether Janeway's statement even refers to Earth years rather than Vulcan years, so the statement may not be inconsistent after all, since the duration of a Vulcan year has not been established.) In the Enterprise episode "AWAKENING," Minister Kuvak of the Vulcan High Command states that Earth and Vulcan have been allies for 100 years. The episode takes place in the middle of the year 2154, and apparently refers to first contact between Earth and Vulcans on April 5, 2063, a span of more than 91 Earth years. Since Vulcans are known to quote numbers with great precision, and the statement about 100 years was made between two Vulcans on the planet Vulcan with no humans present, it would be reasonable to assume they were describing the time span in Vulcan years. If so, then 100 Vulcan years is about 91 Earth years, so one Vulcan year would be about 0.91 Earth year. Therefore, Tuvok's age of 111 Earth years would be equivalent to about 121 Vulcan years, making Janeway's statement in "FURY" about him soon reaching "the big three digits" inaccurate in both Earth and Vulcan years.

Star Trek : Stardate Calculator

Tool will convert standard dates to stardates and vice versa.

• access_time Stardate Calculator Date YYYY/MM/DD HH:MM Calculate Stardate:
• date_range Date Calculator Stardate Calculate Date:

Star Trek: Here's How Stardates Work

Though its development was surprisingly tough, Star Trek's Stardate has a built-in determination system. Here's how it works.

Star Trek ’s Stardate is an integral part of the franchise. At this point, it has become so elaborate that fans can accurately track the course of events throughout the Trek universe simply by checking the Stardate. Like so much about the first series, it didn’t start out that way. It was created solely to disguise the precise date of the show’s future, and it was only through Trek's  phenomenal success that it grew into something larger. A tangled development process led to confusion about how the system works. In actuality, the basics are quite simple.

The Original Series cemented the concept’s status by repetition. William Shatner’s “Captain’s Log” voice-overs were a strong way to provide plot exposition, and the Stardate sounded like something a space captain would use in the future. It started every episode of the first series, then continued with Patrick Stewart on Star Trek: The Next Generation   and subsequent series. During the build-up to  Star Trek: Discovery 's premiere, Star Trek’s Twitter  began counting off Stardates leading to the in-universe date of the first episode.

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Canonically, Stardates are intended to provide a universal calendar for governments spanning numerous planets and cultures, as well as the normality of spaceships that could surpass the speed of light and thus violate notions of relativity. In The Making of Star Trek book, Roddenberry reveals that he invented it to get around awkward questions of when certain technologies were invented. He planned for the Stardates to advance every episode but didn’t get more specific than that.

That changed when reruns of The Original Series began to air out of order, and sharp-eyed fans noticed the Stardates jumping back and forth every week. Roddenberry struggled to set a measurable timetable to explain the notion, which carried over into the development of The Next Generation , where he was determined to set the record straight. A five-digit code was developed and refined, with a few easy hints to let the writers and fans keep track of it. Star Trek has stuck with it ever since.

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The “rebooted” Stardate and the best spot to explain how it works occurred with The Next Generation series premiere, “Encounter at Farpoint.” The episode began on Stardate 41153.7, which matches the year 2364 on the real-world calendar when the episode supposedly takes place. The digit “4” represents the 24 th century, and the first “1” represents the first season of The Next Generation. The remaining numbers advance throughout the season until season 2 when the “41xxx.x” jumps to “42xxx.x.”

That means 1000 units in Stardate measurement are equivalent to a calendar year on Earth. Subsequent seasons of The Next Generation stuck with that yardstick, as did Star Trek: Deep Space Nine and all series thereafter. It’s not without problems. For example, by following its formula, Stardates were established in the year 2323, well after The Original Series and the first six movies that all used the Stardate system. But it’s been internally consistent, and Michael Burnham’s log entry in Discovery, Season 3, Episode 3, “People of Earth,” mentions the Stardate as 865211.3, which matches the show’s 32nd-century setting.

The inconsistencies may have been part of the reason why Discovery launched forward in time. The Stardates, like a lot of other canon content, were looming uncomfortably close, and the move 900 years into the future let the show find its own rhythm. But it’s a testament to how embedded the Stardate notion has become to Star Trek as a whole  and how it remains useful to the series even with its uneven application.

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