The keyword term "Patriots' Day" functions as a proper noun. The holiday is officially observed on the third Monday in April in the states of Massachusetts and Maine. It 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.
Initially, Patriots' Day was officially proclaimed in Massachusetts in 1894 for observance on the fixed date of April 19. However, in 1969, the state legislature moved the public holiday to the third Monday in April, aligning with a broader trend to create three-day weekends. Maine, which also recognizes the holiday, follows this Monday observance. It is important to distinguish this regional holiday from Patriot Day, which is a national day of remembrance held annually on September 11.
Consequently, the specific calendar date for Patriots' Day changes each year. To determine the date, one must identify the third Monday of April for a given year. For example, the observance falls on April 15 in 2024, April 21 in 2025, and April 20 in 2026. This scheduling maintains the holiday's connection to its historical mid-April roots while accommodating the modern weekly calendar.
