In 2026, Patriots' Day in Massachusetts will be observed on Monday, April 20.
The date is determined by state law, which designates the holiday to be celebrated on the third Monday in April. This system was established in 1969 to create a three-day weekend. The holiday commemorates the anniversary of the Battles of Lexington and Concord, which took place on April 19, 1775, marking the start of the American Revolutionary War.
To calculate the date for any given year, one must identify the third Monday of April on the calendar. For 2026, the Mondays in April fall on the 6th, 13th, 20th, and 27th. Consequently, the third Monday is April 20th, which is the official date of the observance.
