| Millennium: | 2nd Millennium |
|---|---|
| Centuries: | 12th cent. – 13th cent. – 14th cent. |
| Decades: | 1210s 1220s 1230s – 1240s – 1250s 1260s 1270s |
| Years: | 1237 1238 1239 – 1240 – 1241 1242 1243 |
| Gregorian calendar | 1240 MCCXL |
| Ab urbe condita | 1993 |
| Armenian calendar | 689 ԹՎ ՈՁԹ |
| Assyrian calendar | 5990 |
| Bengali calendar | 647 |
| Berber calendar | 2190 |
| English Regnal year | 24 Hen. 3 – 25 Hen. 3 |
| Buddhist calendar | 1784 |
| Burmese calendar | 602 |
| Byzantine calendar | 6748–6749 |
| Chinese calendar | 己亥年 (Earth Pig) 3936 or 3876 — to — 庚子年 (Metal Rat) 3937 or 3877 |
| Coptic calendar | 956–957 |
| Discordian calendar | 2406 |
| Ethiopian calendar | 1232–1233 |
| Hebrew calendar | 5000–5001 |
| Hindu calendars | |
| - Vikram Samvat | 1296–1297 |
| - Shaka Samvat | 1161–1162 |
| - Kali Yuga | 4340–4341 |
| Holocene calendar | 11240 |
| Igbo calendar | 240–241 |
| Iranian calendar | 618–619 |
| Islamic calendar | 637–638 |
| Japanese calendar | En'ō 2 / Ninji 1 (仁治元年) |
| Javanese calendar | 1149–1150 |
| Julian calendar | 1240 MCCXL |
| Korean calendar | 3573 |
| Minguo calendar | 672 before ROC 民前672年 |
| Nanakshahi calendar | −228 |
| Thai solar calendar | 1782–1783 |
The year 1240 BC