| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 10s 20s 30s – 40s – 50s 60s 70s |
| Years: | 37 38 39 – 40 – 41 42 43 |
| 40 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 40 XL |
| Ab urbe condita | 793 |
| Armenian calendar | N/A |
| Assyrian calendar | 4790 |
| Bahá'í calendar | -1804–-1803 |
| Bengali calendar | -553 |
| Berber calendar | 990 |
| English Regnal year | N/A |
| Buddhist calendar | 584 |
| Burmese calendar | -598 |
| Byzantine calendar | 5548–5549 |
| Chinese calendar | 己亥年十一月廿八日 (2676/2736-11-28) — to —
庚子年十一月初九日(2677/2737-11-9) |
| Coptic calendar | -244–-243 |
| Ethiopian calendar | 32–33 |
| Hebrew calendar | 3800–3801 |
| Hindu calendars | |
| - Vikram Samvat | 96–97 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3141–3142 |
| Holocene calendar | 10040 |
| Iranian calendar | 582 BP – 581 BP |
| Islamic calendar | 600 BH – 599 BH |
| Japanese calendar | |
| Korean calendar | 2373 |
| Minguo calendar | 1872 before ROC 民前1872年 |
| Thai solar calendar | 583 |
Year 40 (XL) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus without colleague (or, less frequently, year 793 Ab urbe condita). The denomination 40 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.