Determining Calendar Dates From Stardates

Note: The following Stardate calculations are meant to express general trends across all episodes of each Star Trek series. These calculations are not meant to be accurate for small time scales, such as hours or minutes within a single episode.

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1. Expressing Contemporary Dates as Stardates ()
2. Twenty-fourth Century Stardates (TNG, DS9, Voyager)
3. TNG Stardate Calculator
4. Twenty-third Century Stardates (The Original Series)
5. TOS Stardate Calculator
6. Late Twenty-third Century Stardates (The Movie Series)
7. Star Trek XI Stardates
8. Stardate Inconsistencies
• Stardate-to-year ratios
• Tuvok's Birthday
9. Other useful date calculators:
   
   • Calculate duration between two dates
     
   • Add to, or subtract from, a date

Expressing Contemporary Dates as Stardates

Find the fictional Stardate that corresponds to "today's" date

Since the Stardate systems used in various Star Trek episodes are meant to measure time in the Twenty-third and Twenty-fourth Centuries, the same Stardate system cannot be used to express contemporary dates (i.e., in the Twentieth and Twenty-first Centuries).

However, for those who would like to create Stardates to represent contemporary dates, there are three methods that can be used:

1. Represent the current date in YYMM.DD format, where "YY" is the current year minus 1900, MM is the current month (01-12), and DD is the current day of the month (01-31).
   
   For example, September 08, 1966, would be written as "Stardate 6609.08" in the YYMM.DD format. Another digit must be added for years after 1999, such that September 11, 2001, would be written as "Stardate 10109.11" in the YYMM.DD format. This system can be used to express any year after 1900 in Stardate format.
   
   This system also roughly corresponds to the Stardates used in the first six Star Trek motion pictures, such that if a new movie were made today in The Original Series continuity, then its Stardate would be close to the YYMM.DD format.
   
   
2. Using the new Stardate format in Star Trek XI, dates may be expressed in YYYY.xx format, where YYYY is the actual four-digit year, and .xx represents the fraction of the year to two decimal places (i.e., hundredths of a year). For example, January 1, 1999, would correspond to Stardate 1999.00, while July 2, 1999, would correspond to Stardate 1999.50 (half-way through the year 1999).
   
   For any given date, simply calculate the number of days it has been since January 1, then express that as a percentage of the year (the number of days since January 1 divided by 365 should give the number to follow the decimal in the Stardate).
   
   
3. Use the Stardate of the current Star Trek episode or movie to represent today's Stardate. , using The Next Generation Stardate system (i.e., that would be the Stardate of this week's episode if The Next Generation and its spinoffs were still in production).
   
   To express other contemporary dates in The Next Generation Stardate format, use the calculator below.

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 a few basic assumptions.

Fact: The Next Generation episode "The Neutral Zone" gave the calendar year as 2364 at the end of the first season; the episode aired the week of May 18, 1988, with a Stardate of 41986.0.

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. The episode first aired on February 20, 1995, 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 (though the episode was filmed at the end of the first season); the episode aired on August 28, 1995, 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, and the episode originally aired on May 5, 1999 -- less than 11 years after "The Neutral Zone." (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; the episode aired May 9, 2001 -- less than 13 years after "The Neutral Zone."

Fact: An average Earth year comprises about 365.2422 mean solar days.

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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,").

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Assumption: It is generally accepted that Stardates represent one-thousandth of a calendar year -- i.e., there is one year between Stardates 51000.0 and 52000.0.

Conclusion: The Voyager episode "HOMESTEAD" had the Stardate 54868.6 on April 6 (the day after First Contact Day) in the year 2377, since the episode's Stardate and air date are both less than 13 years after those for "The Neutral Zone," whose year was 2364.

Given the above facts and assumption, it is clear that the calendar date April 6, 2377, falls on Stardate 54868.6 at the end of Voyager's final season. From this information, one can determine when Stardates roll over -- i.e., the Stardate "New Year" -- in relation to the calendar year on Earth.

On April 6, 2377, Stardate 54868.6 would be 0.8686 of the way to the end of Stardate year 54000. If Stardates represent thousandths of a year, and an average Earth year comprises about 365.2422 mean solar days, then April 6, 2377, is 317.249375 days into Stardate year 54000. (0.8686 x 365.2422 days = 317.249375 days)

Therefore, Stardate 55000.0 takes place 47.992825 days after April 6, 2377. (55000.0 - 54868.6 = 00131.4 Stardates = 0.1314 year = 47.992825 days)

So, with some simple arithmetic, one can see that Stardate 55000.0 falls on May 24, 2377, making May 24 or May 25 the Stardate New Year on Earth (depending on leap years on the Earth calendar). Knowing this, one can calculate the actual calendar date for any episode with a Stardate in The Next Generation, Deep Space Nine, and Voyager.

For example, the final episode of Voyager -- "ENDGAME" -- had a Stardate of 54973.4. This is 38.2774 days after April 6, 2377, in "HOMESTEAD" (54973.4 - 54868.6 = 00104.8 Stardates = 0.1048 year = 38.2774 days) and it is 9.7154425 days before May 24, 2377, the New Year of Stardate 55000.0 (55000.0 - 54973.4 = 00026.6 Stardates = 0.0266 year = 9.7154 days), so the final episode of Voyager took place the week of May 14, 2377.

As another example, the Voyager episode "THE 37's" had a Stardate of 48975.1, which would put it 9.09453 days before the Stardate New Year of 49000.0 on May 24, 2371 (49000.0 - 48975.1 = 00024.9 Stardates = 0.0249 year = 9.0945 days). Therefore, based on the above calculations, "THE 37's" took place on May 15, 2371. Dialogue in the episode confirms that it took place in 2371; the Stardate (48975.1) is less than seven years after "The Neutral Zone" (41986.0), in which dialogue gave the calendar year as 2364, and less than six years before "HOMESTEAD" (54868.6), which, as proven above, took place on April 6, 2377.

The Next Generation episode "Data's Day" took place on Stardate 44390.1, during the Hindu festival of lights. Based on the above calculations, Stardate 44390.1 would be on Friday, October 14, 2366, which is consistent with the celebration of a fall Hindu festival.

The Voyager episode "NON SEQUITUR" established that Harry Kim graduated from Starfleet Academy on Stardate 47918. Based on the above conclusions, this calculates to April 24, 2370 -- slightly less than seven years (6950.6 Stardates) before "HOMESTEAD," whose date was April 6, 2377, on Stardate 54868.6. (54868.6 - 47918 = 6950.6 Stardates) April 24, 2370, is a reasonable date for an Academy graduation.

The Voyager episode "THE GIFT" established that Annika Hansen (Seven of Nine) was born on Stardate 25479 at the Tendara colony. According to the above calculations, that would be on November 16, 2347, making her over 25 years old in that episode (in 2373).

So, assuming that there are exactly 1,000 Stardates per year, all the episodes cited above are consistent with one another regarding given Stardates, calendar dates, and years. Using these calculations, one can calculate the first Stardate in this system, which would be 54868.6 Stardates before April 6, 2377, or 54.8686 years, meaning that Stardate 00000.0 began on May 25, 2322, at 00:00 hours.

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, given a few basic assumptions and further Stardate facts from episodes of The Original Series.

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 Sunday, April 24, 2366. Thus, for Picard's statement to be true on that date, Sarek would have been born between April 25, 2163 and April 24, 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 1, 2265, and September 30, 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 1, 2265, and September 30, 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 1277.1 in "WHERE NO MAN HAS GONE BEFORE," and the latest Stardate was 5943.7 in "ALL OUR YESTERDAYS," a difference of 4666.6 Stardates. (5943.7 - 1277.1 = 4666.6 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: Thanksgiving in "CHARLIE X" took place before the episode "JOURNEY TO BABEL" -- which, as determined above, took place between October 1, 2265, and September 30, 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).

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.

Fact: 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 about 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.

Conclusion: Having established above that Stardate 1533.7 is on November 23, 2265, and that Stardate 3842.4 must be between October 1, 2265, and September 30, 2266, the maximum span between Stardates 1533.7 and 3842.4 (a difference of 2308.7 Stardates) can be no more than 311 days (or 0.85148977856 year). Therefore, there must be at least 2711.3654892 Stardates per year (or at least 7.4234726688 Stardates per day).

This means that Stardate 0000.0 -- 1533.7 Stardates before November 23, 2265, in "CHARLIE X" -- must have started 0.56565594204 year (206.60142071 days) before that episode. So, assuming the lowest possible Stardate-to-year ratio of 2711.3654892 Stardates per year, Stardate 0000.0 began on Monday, May 1, 2265.

Given the above starting point and the assumed ratio of 2711.3654892 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 1, 2266, just a few months after the Christmas party referred to in the episode.

So the earliest Stardate in The Original Series -- 1277.1 in "WHERE NO MAN HAS GONE BEFORE" took place on October 20, 2265, and the latest Stardate -- 5943.7 in "ALL OUR YESTERDAYS" -- was on July 10, 2267. (The earliest Stardate in The Animated Series -- 1254.4 in "THE MAGICKS OF MEGAS-TU" -- would have taken place on October 16, 2265, and the latest Stardate -- 7403.6 in "BEM" -- would have taken place on January 23, 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.

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 June 28, 2266. Therefore, Stardate 8130.4 must take place after June 28, 2281.

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.

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 5, 2266, then Stardate 9521 must be at least 29 years after October 5, 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 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).

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, 1277.1 in "WHERE NO MAN HAS GONE BEFORE," which would be around October 20, 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, 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 on January 15 in some year after 2283.

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.

In the Voyager episode "EYE OF THE NEEDLE," Commander Chakotay states that the current year is 2371. The episode first aired on February 20, 1995, with a Stardate of 48579.4, less than seven years after "The Neutral Zone," which took place in 2364, and more than six years before Stardate 54868.6 in "HOMESTEAD," which, as calculated above, was on April 6, 2377. Therefore, "EYE OF THE NEEDLE" should have taken place on December 22, 2370, over a week before 2371, in order to be consistent with the date given in "HOMESTEAD."

In the episode "FUTURE'S END," information downloaded from the U.S.S. Voyager's computer indicated that the Voyager was launched in the year 2371. The first episode of Voyager, "CARETAKER," took place on Stardate 48315.6, less than six years and four months after Stardate 41986.0 in "The Neutral Zone" -- which was set in 2364 -- and more than six and a half years before Stardate 54868.6 in "HOMESTEAD," which, as calculated above, was on April 6, 2377. This means that "CARETAKER" must have taken place on September 16, 2370, three and a half months before 2371.

In the episode "HOMESTEAD," Neelix said the crew was celebrating the 315th anniversary of the Vulcans' arrival on Earth. The movie STAR TREK: FIRST CONTACT established that date as April 5, 2063, which would make "HOMESTEAD" the 314th anniversary -- so the only possible conclusion from all available information is that Neelix can't count. "HOMESTEAD" was definitely in 2377, 314 years after First Contact, since its Stardate (54868.6) was less than 13 years after "The Neutral Zone" (41986.0), which was clearly established to be in 2364. (2364 + 13 = 2377)

The Voyager episode "UNIMATRIX ZERO" PART II had a Stardate of 54014.4 at the beginning of the seventh season (Part I did not have a given Stardate). The episode aired on October 4, 2000, more than 12 years after "The Neutral Zone." In the Voyager episode "ENDGAME," a Starfleet cadet stated that the Unimatrix Zero incident took place in the year 2377. However, the Stardate for "UNIMATRIX ZERO" PART II (54014.4) would place it 311.9899 days before the episode "HOMESTEAD," (54868.6), whose given date was April 6. (54868.6 - 54014.4 = 00854.2 Stardates = 0.8542 year = 311.9899 days)

Therefore, "UNIMATRIX ZERO" PART II must have taken place the week of May 29 the year before "HOMESTEAD," whose Stardate (54868.6) was less than 13 years after "The Neutral Zone" (41986.0), which was clearly established to be in 2364. Given these facts, "UNIMATRIX ZERO" PART II must have taken place on May 29, 2376, based on the Stardates and actual date references in other episodes. So the Starfleet cadet in "ENDGAME," speaking on his first day of class, was off by six months in his description of events in "UNIMATRIX ZERO" PART II.

Stardate-to-year ratios:

• 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 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, and Chakotay later mentioned that it was May 20 (Captain Janeway's birthday).
  
  In "YEAR OF HELL, PART II," on Day 133 a captain's log was recorded on Stardate 51425.4. 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. On Day 1 after the timeline is restored, a captain's log is recorded on Stardate 51252.3. 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. In STAR TREK: FIRST CONTACT, a couple days after Stardate 50893.5, Data states that he last used his programming in sexual techniques eight years, seven months, sixteen days, four minutes, twenty-two seconds ago. Therefore, a span of 9684.2 Stardates would be less than eight years, seven months, sixteen days (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).

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 generally accepted ratio of "1,000 Stardates per year" 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 9 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 5, 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 5, 2266, Tuvok would be less than 106 years old on Stardate 50126.4 in "FLASHBACK," which would be on July 9, 2372, 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 5, 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 2376 (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 2276, making him 10 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 5, 2266 (TOS Stardate 3877.4), making him 111 years old on October 5, 2377, just a year after "FURY." (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.