Public holidays
1666, Russia
| # | Date | Public holiday |
|---|---|---|
| 1 | Friday, 1 January 1666 | New Year Holiday |
| 2 | Saturday, 2 January 1666 | New Year Holiday |
| 3 | Sunday, 3 January 1666 | New Year Holiday |
| 4 | Monday, 4 January 1666 | New Year Holiday |
| 5 | Tuesday, 5 January 1666 | New Year Holiday |
| 6 | Wednesday, 6 January 1666 | New Year Holiday |
| 7 | Thursday, 7 January 1666 | New Year Holiday |
| 8 | Friday, 8 January 1666 | New Year Holiday |
| 9 | Tuesday, 23 February 1666 | Defender of the Fatherland Day |
| 10 | Monday, 8 March 1666 | Women's Day |
| 11 | Wednesday, 28 April 1666 | Orthodox Easter |
| 12 | Saturday, 1 May 1666 | Spring and Labour Day |
| 13 | Monday, 3 May 1666 | Spring and Labour Day |
| 14 | Sunday, 9 May 1666 | Victory Day |
| 15 | Monday, 10 May 1666 | Victory Day |
| 16 | Saturday, 12 June 1666 | Russia Day |
| 17 | Monday, 14 June 1666 | Russia Day |
| 18 | Thursday, 4 November 1666 | Unity Day |