For reference, the following were last year's recognized Institute Holidays and Special Holidays and the day/dates on which they were observed. See current holidays.
| Holiday | Day | Date observed |
|---|---|---|
| Martin Luther King, Jr. Day |
3rd Monday in January | Monday, January 18, 2021 |
| Presidents' Day |
3rd Monday in February | Monday, February 15, 2021 |
| Patriots' Day |
3rd Monday in April | Monday, April 19, 2021 |
| Memorial Day |
Last Monday in May | Monday, May 31, 2021 |
| Juneteenth |
June 19 | Friday, June 18, 2021 |
| Special Holiday Closing |
July 2 | Friday, July 2, 2021 |
| Independence Day |
July 4 | Monday, July 5, 2021 |
| Labor Day |
1st Monday in September | Monday, September 6, 2021 |
| Indigenous Peoples Day |
2nd Monday in October | Monday, October 11, 2021 |
| Veterans' Day |
November 11 | Thursday, November 11, 2021 |
| Thanksgiving Day |
4th Thursday in November | Thursday, November 25, 2021 |
| Day After Thanksgiving |
Day after Thanksgiving | Friday, November 26, 2021 |
| Christmas Day |
December 25 | Friday, December 24, 2021 |
| Winter Break |
December 27 | Monday, December 27, 2021 |
| Winter Break |
December 28 | Tuesday, December 28, 2021 |
| Winter Break |
December 29 | Wednesday, December 29, 2021 |
| Winter Break |
December 30 | Thursday, December 30, 2021 |
| New Year's Day |
January 1 | Friday, December 31, 2021 |