21 is a year in the 1st century. It was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Caesar.

Millennium: 1st millennium
Centuries: 1st century BC1st century2nd century
Decades: 0s BC  0s  10s  – 20s –  30s  40s  50s
Years: 18 19 202122 23 24
AD 21 in other calendars
Gregorian calendarAD 21
XXI
Ab urbe condita774
Assyrian calendar4771
Balinese saka calendarN/A
Bengali calendar−572
Berber calendar971
Buddhist calendar565
Burmese calendar−617
Byzantine calendar5529–5530
Chinese calendar庚辰(Metal Dragon)
2717 or 2657
    — to —
辛巳年 (Metal Snake)
2718 or 2658
Coptic calendar−263 – −262
Discordian calendar1187
Ethiopian calendar13–14
Hebrew calendar3781–3782
Hindu calendars
 - Vikram Samvat77–78
 - Shaka SamvatN/A
 - Kali Yuga3121–3122
Holocene calendar10021
Iranian calendar601 BP – 600 BP
Islamic calendar619 BH – 618 BH
Javanese calendarN/A
Julian calendarAD 21
XXI
Korean calendar2354
Minguo calendar1891 before ROC
民前1891年
Nanakshahi calendar−1447
Seleucid era332/333 AG
Thai solar calendar563–564
Tibetan calendar阳金龙年
(male Iron-Dragon)
147 or −234 or −1006
    — to —
阴金蛇年
(female Iron-Snake)
148 or −233 or −1005

Events change

Deaths change