| AD |
In English, Anno Domini. Equivalent to "after Christ". |
| BC |
In English, Before Christ. Equivalent to "before Christ". |
| BE |
Buddhist Era (Thailand), or phutthasakarat. |
| CE |
In English, Common Era. Equivalent to AD (for those who prefer not to refer to Christ). |
| BCE |
In English, Before the Common Era. Equivalent to BC (for those who prefer not to refer to Christ). |
| JD |
In English, Julian Day. Julian-day count in the Julian period. |
| MJD |
In English, Modified Julian Day. |
| DJM |
Modified Julian Date. |
| AM |
Hebrew year. Anno Mundi: year of the world. = 3761 BC |
| AH |
Islamic year. Anno Hegirae, or year of the Hijra. = 16 July 622 AD |
| S |
Solar Hijri calendar (Iran and Afghanistan) |
| AC |
Ab Urbe Condita (from the founding of Rome) |
| BP |
Before Present (before 1950) |
| GMT |
Greenwich Mean Time |
| TAI |
International Atomic Time |
| TE |
Ephemeris Time |
| UT (TU) |
Universal Time |
| UTC |
Coordinated Universal Time |
| DST |
Daylight Saving Time (summer/winter clock change system) |
