Public holidays
1661, USA, Illinois
| # | Date | Public holiday |
|---|---|---|
| 1 | Saturday, January 1, 1661 | New Year's Day |
| Friday, February 11, 1661 | Lincoln's Birthday (observance) | |
| 2 | Saturday, February 12, 1661 | Lincoln's Birthday |
| 3 | Tuesday, February 22, 1661 | Washington's Birthday |
| 4 | Monday, May 30, 1661 | Memorial Day |
| 5 | Monday, July 4, 1661 | Independence Day |
| 6 | Monday, September 5, 1661 | Labor Day |
| 7 | Tuesday, November 8, 1661 | Election Day |
| 8 | Sunday, December 25, 1661 | Christmas |
| Monday, December 26, 1661 | Christmas (observance) |