Date Conversion: Each Major Race uses their own dating system, rendering date conversion between systems necessary on occasion. The following article outlines the workings of each system and defines the reference date that determines year 0 in each and how to convert dates between various systems.
- 1 Description (Specifications)
- 2 History & Background (Dossier)
- 3 References & Contributors (Sources)
Equivalent Dates of Charted Space: Here is a set of dates comparatively dated to several calendars in common usage throughout Charted Space:
|3621 BC||-8145||3,148 PI||-639.1||-5,442||1||Start of K'Kree calendar|
|2208 BC||-6731||2,046 PI||1.1||-5,301||1,186||Start of Zhodani calendar|
|AD 1||-4520||361 PI||981.2||-2,779||3027||Solomani calendar begins|
|AD 475||-4045||1 VI||1,192.2||-2,237||3,422||Start of Vilani calendar|
|AD 2436||-2083||1,496 VI||2,058.3||0||5,055||Aslan calendar Begins|
|AD 4518||0||3,084||2,979.3||2,376||6,788||Start of Imperial calendar|
Read down for date of origin, then across to calendar to convert.
|Source (x)||to Solomani||to Imperial||to Vilani||to Zhodani||to Aslan||to K'Kree||to Hiver|
|from Solomani||n/a||(x - 4521) / 1.0006644|
|from Imperial||(x * 1.0006644) + 4521||n/a||(x + 4045)/1.312||(x + 6731)/2.26||(x + 2083) / 0.877||(x + 8145) / 1.2||(x - 410)*2|
|from Vilani||(x * 1.312) - 4045||n/a|
|from Zhodani||(x * 2.26) - 6731||n/a|
|from Aslan||(x * 0.877) -2083||n/a|
|from K'Kree||(x * 1.2) - 8145||n/a|
|from Hiver||(x/2) + 410||n/a|
NOTES: Note that converting from a calendar that does not have a zero year (e.g. Solomani, Vilani, Zhodani, K'kree) i.e. the 0 point is an instant in time, rather than a complete year, must account for the "missing" year when going from "negative" dates to positive ones.
History & Background (Dossier)
Primary Calendars of the Imperium: As the largest and most dominant polity, the calendars of the Imperium have been central to interstellar trade and history although despite their wide use, they are still not an official or standardized galactic calendar.
- Main article: Imperial calendar
The Third Imperium uses a regularized version of the calendar originally developed on Terra. It shares seconds, minutes, hours, days and weeks with the Solomani version, but does not organize them into intermediate months. The Imperial year is exactly 365 days, or 52 weeks with one extra "Holiday" date. The calendar is, naturally, tied to the declaration of the founding of the Imperium by Cleon I.
- Main article: Revised Gregorian Calendar
The Solomani have kept the same dating system that was in use before the Solomani invention of jump drive and coming into contact with the Ziru Sirka. Its reference date is tied to the birth of a popular religious figure from early Terran history.
The Imperial Calendar is heavily influenced by the Solomani dating system, and borrows most of its basic timekeeping units. However, instead of numbering days within a year, as in Imperial practice, days are numbered inside a month, twelve roughly equal subdivisions of the year. Further, the length of the year is subtly different as Solomani calendar still periodically adjusts to synchronize with the sidereal period of Terra around Sol (365.2425 days, thus the Solomani year is 1.0006644 Imperial years). Because of this difference, the first day of the two calendars are 0.74 years apart as of 1116.
Other Major Race Calendars of Charted Space
Many other races employ calendars and time-keeping systems of importance to trade and history.
- Main article: Aslan calendar
- Main article: Hiver calendar
Hive Federation dates begin with the official proclaiming of Glea as the Federation capital. This occurred in 410 imperial, though the move was not officially completed until 490. While all official dates refer to this calendar, most Hiver nests use local dating systems.
A Cycle (day) is a little over 22 hours. A year is 143 cycles, each cycle simply numbered 1 to 143 with no month or week divisions. Thus, a Hiver year is about half an Imperial one (0.49 specifically).
1105 is 1389 HF; 1111 is 1401 HF (from CT AM 7 HIvers).
- Main article: K'kree calendar
Vargr have no accurate calendar, so dating is meaningless, however a Vargr "year" is ~1.03 Solomani years.
- Main article: Zhodani calendar
The Zhodani chten is ~0.754 standard years. The calendar uses Olympiads, which is three chten, with an extra day to cover the leap years. An Olympiad is ~2.262 standard years. The Zhodani calendar uses the count of olympiad from the founding of the Psionic Games, plus a marker of which year (1, 2, or 3) into the current olympiad (e.g. 1244.1).
Minor Race Calendars of Note
No information yet available.
References & Contributors (Sources)
- John Harshman, Marc Miller, Loren Wiseman. Library Data (A-M) (Game Designers Workshop, 1981), 10.
- Marc Miller. The Traveller Book (Game Designers Workshop, 1982), 152-153.
- J. Andrew Keith, Marc Miller, John Harshman. Aslan (Game Designers Workshop, 1984), 36.
- J. Andrew Keith, Marc Miller, John Harshman. Zhodani (Game Designers Workshop, 1985), 8.
- John Harshman, Marc Miller. Solomani (Game Designers Workshop, 1986), 12.
- Marc Miller. Imperial Encyclopedia (Game Designers Workshop, 1987), 6-7.
- Marc Miller. Referee's Companion (Game Designers Workshop, 1988), 42-45.
- Lester Smith. Milieu 0 (Imperium Games, 1996), 89-91.
- Loren Wiseman. GURPS Traveller Core Rules (Steve Jackson Games, 1998), 15-19.
- Andy Slack, David Thomas, David L. Pulver. Alien Races 2 (Steve Jackson Games, 1999), 19.