The holiday was originally celebrated on April 19, the actual anniversary of the battles (fought in 1775). Since 1969, it has been observed on the third Monday in April in Massachusetts and in Maine (which until the Missouri Compromise of 1820 was part of Massachusetts). The Monday holiday creates a three-day long weekend. It is also the first day of a vacation week for public schools in both states and a school holiday for many local colleges and universities, both public and private.
The day is a public school observance day in Wisconsin. Florida law also encourages people to celebrate it, though it is not treated as a public holiday. Connecticut began observance in 2018.
Acton Minutemen and citizens marching from Acton to Concord on Patriots' Day 2012
Observances and re-enactments of the battles occur annually at Lexington Green in Lexington, Massachusetts (around 6:00 am) and the Old North Bridge in Concord, Massachusetts (around 9:00 am). In the morning, mounted re-enactors with state police escorts retrace the Midnight Rides of Paul Revere and William Dawes, calling out warnings the whole way.
The most significant celebration of Patriots' Day is the Boston Marathon, which has been run every Patriots' Day since April 19, 1897 to mark the then-recently established holiday, with the race linking the Athenian and American struggles for liberty (marathons being so named after the Greek Battle of Marathon).