The keyword phrase is an interrogative clause, with the subject "Patriots' Day" functioning as a proper noun. In the context of the year 2026, the holiday will be observed on Monday, April 20. This date is determined by its designation as a state holiday in Massachusetts and Maine, where it is legally mandated to occur on the third Monday of April.
The specific date is calculated by identifying the calendar structure for April 2026. The first day of that month is a Wednesday. Consequently, the first Monday is April 6, the second is April 13, and the third Monday falls on April 20. This "floating Monday" rule was established to create a three-day weekend, shifting the observance from its historical anniversary date of April 19, which marks the Battles of Lexington and Concord in 1775.
The primary practical application of this date is the scheduling of the Boston Marathon, which is traditionally held on Patriots' Day each year. Therefore, the 130th Boston Marathon will take place on April 20, 2026. For residents of the observing states, the day also means the closure of state, county, and municipal offices, as well as many schools and businesses, impacting public and commercial activities.
