A holiday in honor of Christopher Columbus arrival to America on October 12th, 1492. For some reason, it is celebrated on the second Monday of October. That makes zero sense.

A day about labor? Celebrated on the first Monday of September.

A holiday in honor of those who died in the armed services, celebrated on the last Monday of May.

A U.S. federal holiday celebrated on the third Monday of February. People don't care about this one much.