20 BC

Millennium:	1st millennium BC
Centuries:	2nd century BC 1st century BC 1st century
Decades:	40s BC 30s BC 20s BC 10s BC 0s BC
Years:	23 BC 22 BC 21 BC 20 BC 19 BC 18 BC 17 BC

20 BC in various calendars
Gregorian calendar	20 BC XIX BC
Ab urbe condita	734
Ancient Greek era	190th Olympiad (victor )¹
Assyrian calendar	4731
Bengali calendar	−612
Berber calendar	931
Buddhist calendar	525
Burmese calendar	−657
Byzantine calendar	5489–5490
Chinese calendar	庚子年 (Metal Rat) 2677 or 2617 — to — 辛丑年 (Metal Ox) 2678 or 2618
Coptic calendar	−303 – −302
Discordian calendar	1147
Ethiopian calendar	−27 – −26
Hebrew calendar	3741–3742
Hindu calendars
- Vikram Samvat	37–38
- Shaka Samvat	N/A
- Kali Yuga	3081–3082
Holocene calendar	9981
Iranian calendar	641 BP – 640 BP
Islamic calendar	661 BH – 660 BH
Javanese calendar	N/A
Julian calendar	20 BC XIX BC
Korean calendar	2314
Minguo calendar	1931 before ROC 民前1931年
Nanakshahi calendar	−1487
Seleucid era	292/293 AG
Thai solar calendar	523–524
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Year 20 BC was either a common year starting on Wednesday or Thursday or a leap year starting on Tuesday, Wednesday or Thursday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Tuesday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Appuleius and Nerva (or, less frequently, year 734 Ab urbe condita). The denomination 20 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.