| Millennium: | 1st millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 640 by topic |
|---|
| Leaders |
| Categories |
| Gregorian calendar | 640 DCXL |
| Ab urbe condita | 1393 |
| Armenian calendar | 89 ԹՎ ՁԹ |
| Assyrian calendar | 5390 |
| Balinese saka calendar | 561–562 |
| Bengali calendar | 47 |
| Berber calendar | 1590 |
| Buddhist calendar | 1184 |
| Burmese calendar | 2 |
| Byzantine calendar | 6148–6149 |
| Chinese calendar | 己亥年 (Earth Pig) 3337 or 3130 — to — 庚子年 (Metal Rat) 3338 or 3131 |
| Coptic calendar | 356–357 |
| Discordian calendar | 1806 |
| Ethiopian calendar | 632–633 |
| Hebrew calendar | 4400–4401 |
| Hindu calendars | |
| - Vikram Samvat | 696–697 |
| - Shaka Samvat | 561–562 |
| - Kali Yuga | 3740–3741 |
| Holocene calendar | 10640 |
| Iranian calendar | 18–19 |
| Islamic calendar | 19–20 |
| Japanese calendar | N/A |
| Javanese calendar | 530–531 |
| Julian calendar | 640 DCXL |
| Korean calendar | 2973 |
| Minguo calendar | 1272 before ROC 民前1272年 |
| Nanakshahi calendar | −828 |
| Seleucid era | 951/952 AG |
| Thai solar calendar | 1182–1183 |
| Tibetan calendar | 阴土猪年 (female Earth-Pig) 766 or 385 or −387 — to — 阳金鼠年 (male Iron-Rat) 767 or 386 or −386 |
Year 640 (DCXL) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. The denomination 640 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.