The keyword term itself is an interrogative clause functioning as a noun phrase, with the core components being the proper nouns "Patriots' Day" and "Boston Marathon." The Boston Marathon is held annually on Patriots' Day, a state holiday observed in Massachusetts and Maine. This holiday is statutorily set on the third Monday in April.
The specific calendar date of the event changes each year because it is tied to a day of the week rather than a fixed number. For example, the race occurred on April 15, 2024; it is scheduled for April 21, 2025, and April 20, 2026. This tradition dates back to the marathon's inception in 1897, when the Boston Athletic Association aligned its new race with the recently established holiday commemorating the first battles of the American Revolutionary War.
Consequently, the date of the Boston Marathon is consistently determined by the observance of Patriots' Day. To find the date in any given year, one must identify the third Monday of that April. This scheduling ensures the event takes place on a public holiday within its primary jurisdiction, facilitating a large-scale public event with significant spectator and volunteer involvement.
