Public holidays
1666, United Kingdom, Northern Ireland
| # | Date | Public holiday |
|---|---|---|
| 1 | Friday, 1 January 1666 | New Year's Day |
| 2 | Wednesday, 17 March 1666 | St. Patrick's Day |
| 3 | Friday, 16 April 1666 | Good Friday |
| 4 | Monday, 19 April 1666 | Easter Monday |
| 5 | Monday, 3 May 1666 | Early May Bank Holiday |
| 6 | Monday, 31 May 1666 | Spring Bank Holiday |
| 7 | Monday, 12 July 1666 | Orangemen's Day |
| 8 | Monday, 30 August 1666 | Late Summer Bank Holiday |
| 9 | Monday, 27 December 1666 | Christmas Day (substitute day) |
| 10 | Tuesday, 28 December 1666 | Boxing Day (substitute day) |