Calendar era

A calendar era is the year numbering system used by a calendar. The Gregorian calendar for example numbers its years in the Western Anno Domini system (the Coptic Orthodox and Ethiopian Orthodox churches have their own Christian eras). The instant, date, or year from which time is marked is called the epoch of the era. There are many different calendar eras such as Saka Era.

2025 in other calendars

Gregorian calendar	2025 MMXXV
Ab urbe condita	2778
Armenian calendar	1474 ԹՎ ՌՆՀԴ
Assyrian calendar	6775
Bahá'í calendar	181–182
Balinese saka calendar	1946–1947
Bengali calendar	1432
Berber calendar	2975
British Regnal year	3 Cha. 3 – 4 Cha. 3
Buddhist calendar	2569
Burmese calendar	1387
Byzantine calendar	7533–7534
Chinese calendar	甲辰年 (Wood Dragon) 4721 or 4661     — to — 乙巳年 (Wood Snake) 4722 or 4662
Coptic calendar	1741–1742
Discordian calendar	3191
Ethiopian calendar	2017–2018
Hebrew calendar	5785–5786
Hindu calendars
- Vikram Samvat	2081–2082
- Shaka Samvat	1946–1947
- Kali Yuga	5125–5126
Holocene calendar	12025
Igbo calendar	1025–1026
Iranian calendar	1403–1404
Islamic calendar	1446–1447
Japanese calendar	Reiwa 7 (令和７年)
Javanese calendar	1958–1959
Juche calendar	114
Julian calendar	Gregorian minus 13 days
Korean calendar	4358
Minguo calendar	ROC 114 民國114年
Nanakshahi calendar	557
Thai solar calendar	2568
Tibetan calendar	阳木龙年 (male Wood-Dragon) 2151 or 1770 or 998     — to — 阴木蛇年 (female Wood-Snake) 2152 or 1771 or 999
Unix time	1735689600 – 1767225599

In ancient times, regnal years were counted from the year a new monarch took the throne. This makes ancient timelines very difficult to reconstruct, because they are based on separate and scattered king lists, such as the Sumerian King List and the Babylonian Canon of Kings. In East Asia, having era names based on ruling monarchs ended in the 20th century except for Japan, where they are still used.