[Porsche-O-Phile]

Patriots Day is a Massachusetts (really just Suffolk County) holiday commemorating the start of the Revolutionary War. It's always the 3rd Monday in April and is the traditional day for the Marathon. The fact that it coincided with "Tax Day" is coincidence - some years it's before, others after, others (like yesterday) on. IIRC MA residents get a tax filing extension until today for state, possibly federal too because of the holiday (or quasi-holiday, whichever - I'm not sure it's even still a formal state holiday anymore in this age of cutbacks and holiday / benefit cuts).