Talk:Imperial Calendar
Notes (2024)[edit]
Alignment to Solomani calendar[edit]
The best "classic" Traveller source for date correspondence between the Imperial Calendar and Solomani calendar is Alien Module 6: Solomani, but the earlier dates seem to have some typos or miscalculations. We have four stated date correspondences:
- 1 Feb 1986 == 111-(-2537) ("Random ancient date", page 30)
- 19 Jan 4521 == 001-0 ("Founding date of the Imperium", page 30)
- 13 Mar 5471 == 292-950 (Empress Margaret orders Terra to be re-integrated into the Imperium, page 11)
- 16 Apr 5631 == 001-1111 ("Approximate current date", page 30)
(We also get told that 13 Mar in 588 IC is when Terra was incorporated into the Imperium, and in 679 IC was when Emperor Zhakirov married Antiama, but no matching Imperial day is provided for either.) The latest two in 950 and 1111 seem to be consistent. The other two do not. However, it seems plausible that "19 Jan 4521" is a typo for "10 Jan 4521", which would be consistent with the other two Imperial-era dates.
In addition, Supplement 8: Library Data (A-M), page 10 also agrees that Imperial year 0 is "4521 AD" [sic]. The first reference that claims Imperial year 0 is AD 4518 is MegaTraveller's Imperial Encyclopedia, and given the number of weird typos in MegaTraveller, I think that unless we can find out why that was changed from the original developers of the project, we can write that off as another error.
| Imperial date | Solomani date |
|---|---|
| 001-0 | 10 Jan 4521 (year is in alignment with Supplement 8: Library Data (A-M) page 10) |
| 001-100 | 17 Dec 4620 |
| 001-200 | 23 Nov 4720 |
| 001-300 | 29 Oct 4820 |
| 001-400 | 5 Oct 4920 |
| 001-500 | 11 Sep 5020 |
| 001-600 | 18 Aug 5120 |
| 001-700 | 24 Jul 5220 |
| 001-800 | 30 Jun 5320 |
| 001-900 | 6 Jun 5420 |
| 292-950 | 13 Mar 5470 (date given in print, aligns to 001-1100 example) |
| 001-1000 | 13 May 5520 |
| 001-1100 | 18 Apr 5620 |
| 001-1110 | 16 Apr 5630 (date given in print, aligns to 292-950 example) |
| 001-1200 | 25 Mar 5720 |
| 001-1300 | 1 Mar 5820 |
| 001-1400 | 6 Feb 5920 |
| 001-1500 | 12 Jan 6020 |
(This shift is logical if you think about it: an Imperial century is 36500 days long. A Gregorian one is either 36524 or 36525 days long, depending on whether the century year is exactly divisible by 400. So the Imperial Holiday will slip backward on the Gregorian calendar by 24 to 25 days a century.)
Day-of-week Problem[edit]
The actual Solomani day-of-week is complicated depending on whether the calendar is still Gregorian or whether the real-life proposal by Sir John Herschel in 1869 is adopted to make years exactly divisible by 4000 not leap years even though they're divisible by 400 and by 4 (see page 671 of https://library.si.edu/digital-library/book/outlinesofastro00hers). It hasn't yet been implemented in the real world, Traveller doesn't specify whether this gets implemented in its future history---and AD 4000 is in the middle of the Long Night so different worlds might make different decisions! Assuming the Old Earth Union makes that change and that becomes the "Solomani calendar", then instead of 16 Apr 5630 being a Tuesday (in the Gregorian calendar), it'll be a Monday (in the Herschelian/Revised Gregorian calendar, due to dropping 29 Feb 4000).
If my math's right, I think that if there is no 29 Feb 4000, and 001-0 is 10 Jan 4521, then March 13 in 588 (the day Terra/Sol joined the Imperium, according to Alien Module 6: Solomani) is Friday the 13th of March 5109, or 204-588 IC. Maybe someone superstitious should have looked at a calendar. Standard Gregorian calendar, it's a Saturday.
Translation (2020)[edit]
The wiki translation team into Spanish has marked this page for translation. Please do not remove the "< translate >" tags. Thank you very much.--Sugaar (talk) 06:52, 6 September 2020 (EDT)
Links (2019)[edit]
- EXTERNAL LINK: What is the first day of the Imperium (001-0000) in the Solomani calendar? I know it's 4518 AD, but is it the 1st of January, or the 28th of May, or what?
- EXTERNAL LINK: How many days in the Imperial calendar?
- - Maksim-Smelchak (talk) 14:42, 21 February 2019 (EST)
Links (2018)[edit]
- EXTERNAL LINK: What year is it, by the “official” Imperial calendar? Assuming the clock wasn’t reset by Virus, that is.
- JTAS #1, released in 1979, had an in-setting date of 183-1105 (see the bottom of the table of contents page), so we have just begun 1145 in 2019 CE if we maintain the CT day-for-day progression.
- - Maksim-Smelchak (talk) 16:06, 30 December 2018 (EST)