- Main article: Imperial calendar
- Main article: Revised Gregorian Calendar
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.
VilaniThe Vilani also count from the founding of the Empire Ziru Sirka. Each Vilani year is ~1.312 Solomani year.
- Main article: Zhodani calendar
- Main article: Aslan calendar
- Main article: K'kree calendar
VargrVargr have no accurate calendar, so dating is meaningless, however a Vargr "year" is ~1.03 Solomani years.
DroyneThe Droyne calendar likely should start around -75,000 Imperial, however the Droyne don't keep good records either.
- Main article: Hiver calendar
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).
|3,659 BC||-8,145||3,148 PI||-639.1||-5,442||1||Start of K'Kree calendar|
|2,213 BC||-6,731||2,046 PI||1.1||-5,301||1,186||Start of Zhodani calendar|
|AD 1||-4,520||361 PI||981.2||-2,779||3027||Solomani calendar begins|
|AD 473||-4,045||1 VI||1,192.2||-2,237||3,422||Start of Vilani calendar|
|AD 2435||-2,083||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|
Conversion ChartRead down for date of origin, then across to calendar to convert.
|Solomani||n/a||(x - 4518) / 1.0006644|
|Imperial||(x * 1.0006644) + 4518||n/a||(x + 4045)/1.312||(x + 6731)/2.26||(x + 2083) / 0.877||(x + 8145) / 1.2||(x - 410)*2|
|Vilani||(x * 1.312) - 4045||n/a|
|Zhodani||(x * 2.26) - 6731||n/a|
|Aslan||(x * 0.877) -2083||n/a|
|K'Kree||(x * 1.2) - 8145||n/a|
|Hiver||(x/2) + 410||n/a|
Sources : http://wiki.travellerrpg.com/Date_Conversion