| Millennium: | 2nd millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 1640 by topic |
|---|
| Arts and science |
| Leaders |
| Birth and death categories |
| Births – Deaths |
| Establishments and disestablishments categories |
| Establishments – Disestablishments |
| Works category |
| Gregorian calendar | 1640 MDCXL |
| Ab urbe condita | 2393 |
| Armenian calendar | 1089 ԹՎ ՌՁԹ |
| Assyrian calendar | 6390 |
| Balinese saka calendar | 1561–1562 |
| Bengali calendar | 1047 |
| Berber calendar | 2590 |
| English Regnal year | 15 Cha. 1 – 16 Cha. 1 |
| Buddhist calendar | 2184 |
| Burmese calendar | 1002 |
| Byzantine calendar | 7148–7149 |
| Chinese calendar | 己卯年 (Earth Rabbit) 4337 or 4130 — to — 庚辰年 (Metal Dragon) 4338 or 4131 |
| Coptic calendar | 1356–1357 |
| Discordian calendar | 2806 |
| Ethiopian calendar | 1632–1633 |
| Hebrew calendar | 5400–5401 |
| Hindu calendars | |
| - Vikram Samvat | 1696–1697 |
| - Shaka Samvat | 1561–1562 |
| - Kali Yuga | 4740–4741 |
| Holocene calendar | 11640 |
| Igbo calendar | 640–641 |
| Iranian calendar | 1018–1019 |
| Islamic calendar | 1049–1050 |
| Japanese calendar | Kan'ei 17 (寛永１７年) |
| Javanese calendar | 1561–1562 |
| Julian calendar | Gregorian minus 10 days |
| Korean calendar | 3973 |
| Minguo calendar | 272 before ROC 民前272年 |
| Nanakshahi calendar | 172 |
| Thai solar calendar | 2182–2183 |
| Tibetan calendar | 阴土兔年 (female Earth-Rabbit) 1766 or 1385 or 613 — to — 阳金龙年 (male Iron-Dragon) 1767 or 1386 or 614 |
1640 (MDCXL) was a leap year starting on Sunday of the Gregorian calendar and a leap year starting on Wednesday of the Julian calendar, the 1640th year of the Common Era (CE) and Anno Domini (AD) designations, the 640th year of the 2nd millennium, the 40th year of the 17th century, and the 1st year of the 1640s decade. As of the start of 1640, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.