Patriot’s Day has been a “movable feast” these past 20 years or more. It used to be April 19, but now it’s the third Monday in April or something. Anyway, this year it’s today.
BTW, Paul Revere never made it to Concord to warn the townspeople that the 'Regulars' were coming. He was with two other riders, on the road to Lexington/Concord, when they were stopped by a British Army patrol. One rider got away, and it was he who went on to Concord. Revere and the other rider were held for several hours by the British, and when they were released, went north to Bedford to warn the militia in that area.