Events in August 1866
| MonMonday | TueTuesday | WedWednesday | ThuThursday | FriFriday | SatSaturday | SunSunday |
|---|
| 3030 July 1866 | 3131 July 1866 | 11 August 1866 | 22 August 1866 | 33 August 1866 | 44 August 1866 | 55 August 1866 |
| 66 August 1866 | 77 August 1866 | 88 August 1866 | 99 August 1866 | 1010 August 1866 | 1111 August 1866 | 1212 August 1866 |
| 1313 August 1866 | 1414 August 1866 | 1515 August 1866 | 1616 August 1866 | 1717 August 1866 | 1818 August 1866 | 1919 August 1866 |
| 2020 August 1866 | 2121 August 1866 | 2222 August 1866 | 2323 August 1866 | 2424 August 1866 | 2525 August 1866 | 2626 August 1866 |
| 2727 August 1866 | 2828 August 1866 | 2929 August 1866 | 3030 August 1866 | 3131 August 1866 | 11 September 1866 | 22 September 1866 |