400 BC

Millennium:	1st millennium BC
Centuries:	5th century BC 4th century BC 3rd century BC
Decades:	420s BC 410s BC 400s BC 390s BC 380s BC
Years:	403 BC 402 BC 401 BC 400 BC 399 BC 398 BC 397 BC

400 BC in various calendars

Gregorian calendar	400 BC CCCXCIX BC
Ab urbe condita	354
Ancient Egypt era	XXVIII dynasty, 5
- Pharaoh	Amyrtaeus, 5
Ancient Greek era	95th Olympiad (victor)¹
Assyrian calendar	4351
Bengali calendar	−992
Berber calendar	551
Buddhist calendar	145
Burmese calendar	−1037
Byzantine calendar	5109–5110
Chinese calendar	庚辰年 (Metal Dragon) 2297 or 2237     — to — 辛巳年 (Metal Snake) 2298 or 2238
Coptic calendar	−683 – −682
Discordian calendar	767
Ethiopian calendar	−407 – −406
Hebrew calendar	3361–3362
Hindu calendars
- Vikram Samvat	−343 – −342
- Shaka Samvat	N/A
- Kali Yuga	2701–2702
Holocene calendar	9601
Iranian calendar	1021 BP – 1020 BP
Islamic calendar	1052 BH – 1051 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	1934
Minguo calendar	2311 before ROC 民前2311年
Nanakshahi calendar	−1867
Thai solar calendar	143–144
This box:

Year 400 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Tribunate of Esquilinus, Capitolinus, Vulso, Medullinus, Saccus and Vulscus (or, less frequently, year 354 Ab urbe condita). The denomination 400 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.

...
Wikipedia