It's April 15 -- why do we get until Monday to file tax returns? Because it's a legal holiday today in the District of Columbia -- Emancipation Day, usually celebrated on the 16th but observed on Friday when the 16th is a Saturday. When D.C. has the day off, federal tax deadlines get pushed to the next business day.

In Massachusetts and Maine, Monday is a holiday -- Patriots Day (Paul Revere's ride, and all that) -- and so folks in those states have until Tuesday the 19th to file their state (but not their federal) income tax returns. The federal IRS has a service center in Andover, Massachusetts -- presumably, it will be closed on Monday, but federal returns are still due that day.