Public holidays
1666, USA, Iowa
| # | Date | Public holiday |
|---|---|---|
| 1 | Friday, 1 January 1666 | New Year's Day |
| 2 | Friday, 12 February 1666 | Lincoln's Birthday |
| 3 | Sunday, 30 May 1666 | Memorial Day |
| 4 | Sunday, 4 July 1666 | Independence Day |
| Monday, 5 July 1666 | Independence Day (observance) | |
| 5 | Monday, 6 September 1666 | Labor Day |
| Friday, 24 December 1666 | Christmas (observance)/Christmas Eve | |
| 6 | Saturday, 25 December 1666 | Christmas |
| Friday, 31 December 1666 | New Year's Day (observance) |