Events in December 1840
| MonMonday | TueTuesday | WedWednesday | ThuThursday | FriFriday | SatSaturday | SunSunday |
|---|
| 3030 November 1840 | 11 December 1840 | 22 December 1840 | 33 December 1840 | 44 December 1840 | 55 December 1840 | 66 December 1840 |
| 77 December 1840 | 88 December 1840 | 99 December 1840 | 1010 December 1840 | 1111 December 1840 | 1212 December 1840 | 1313 December 1840 |
| 1414 December 1840 | 1515 December 1840 | 1616 December 1840 | 1717 December 1840 | 1818 December 1840 | 1919 December 1840 | 2020 December 1840 |
| 2121 December 1840 | 2222 December 1840 | 2323 December 1840 | 2424 December 1840 | 2525 December 1840 | 2626 December 1840 | 2727 December 1840 |
| 2828 December 1840 | 2929 December 1840 | 3030 December 1840 | 3131 December 1840 | 11 January 1841 | 22 January 1841 | 33 January 1841 |