420 BC

Millennium: 1st millennium BC
Centuries:
Decades:
Years:
420 BC in various calendars
Gregorian calendar420 BC
CDXX BC
Ab urbe condita334
Ancient Egypt eraXXVII dynasty, 106
- PharaohDarius II of Persia, 4
Ancient Greek era90th Olympiad (victor
Assyrian calendar4331
Balinese saka calendarN/A
Bengali calendar−1012
Berber calendar531
Buddhist calendar125
Burmese calendar−1057
Byzantine calendar5089–5090
Chinese calendar庚申年 (Metal Monkey)
2278 or 2071
    — to —
辛酉年 (Metal Rooster)
2279 or 2072
Coptic calendar−703 – −702
Discordian calendar747
Ethiopian calendar−427 – −426
Hebrew calendar3341–3342
Hindu calendars
 - Vikram Samvat−363 – −362
 - Shaka SamvatN/A
 - Kali Yuga2681–2682
Holocene calendar9581
Iranian calendar1041 BP – 1040 BP
Islamic calendar1073 BH – 1072 BH
Javanese calendarN/A
Julian calendarN/A
Korean calendar1914
Minguo calendar2331 before ROC
民前2331年
Nanakshahi calendar−1887
Thai solar calendar123–124
Tibetan calendar阳金猴年
(male Iron-Monkey)
−293 or −674 or −1446
    — to —
阴金鸡年
(female Iron-Rooster)
−292 or −673 or −1445

Year 420 BC was a year of the pre-Julian Roman calendar. The denomination 420 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.