| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 0s BC 0s 10s – 20s – 30s 40s 50s |
| Years: | 17 18 19 – 20 – 21 22 23 |
| 20 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 20 XX |
| Ab urbe condita | 773 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1824 – -1823 |
| Bengali calendar | -573 |
| Berber calendar | 970 |
| Buddhist calendar | 564 |
| Burmese calendar | -618 |
| Byzantine calendar | 5528 – 5529 |
| Chinese calendar | 己卯年十二月十七日 (2656/2716-12-17) — to —
庚辰年十二月廿八日(2657/2717-12-28) |
| Coptic calendar | -264 – -263 |
| Ethiopian calendar | 12 – 13 |
| Hebrew calendar | 3780 – 3781 |
| Hindu calendars | |
| - Bikram Samwat | 76 – 77 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3121 – 3122 |
| Holocene calendar | 10020 |
| Iranian calendar | 602 BP – 601 BP |
| Islamic calendar | 621 BH – 619 BH |
| Japanese calendar | |
| Korean calendar | 2353 |
| Thai solar calendar | 563 |
Year 20 (XX) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar.