| Years |
|---|
| Millennium |
| 2nd millennium |
| Centuries |
| Decades |
| Years |
| Gregorian calendar | 1240 MCCXL |
| Ab urbe condita | 1993 |
| Armenian calendar | 689 ԹՎ ՈՁԹ |
| Assyrian calendar | 5990 |
| Balinese saka calendar | 1161–1162 |
| 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 |
| Tibetan calendar | ས་མོ་ཕག་ལོ་ (female Earth-Boar) 1366 or 985 or 213 — to — ལྕགས་ཕོ་བྱི་བ་ལོ་ (male Iron-Rat) 1367 or 986 or 214 |
1240 (MCCXL) was a leap year starting on Sunday of the Julian calendar, the 1240th year of the Common Era (CE) and Anno Domini (AD) designations, the 240th year of the 2nd millennium, the 40th year of the 13th century, and the 1st year of the 1240s decade. As of the start of 1240, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.