The two top competitors for Sunday, February 17 are Random Acts of Kindness Day and My Way Day. These may seem contradictory in a way -- doing acts of kindness for others is selfless, doing things your own way might be seen as selfish. But it ain't necessarily so: Your way could be to perform random acts of kindness for friends or strangers. It's probably easier than being nice to grouches anyway.
Alexander Hamilton's unlikely support of Thomas Jefferson helped break the stalemate in the House of Representatives on February 17, 1801, finally ending the presidential election of 1800. With Hamilton's quiet support of Jefferson as the lesser of two evils, Hamilton was set on a collision course with Aaron Burr, the man who became Jefferson's Vice President. Their paths would cross for the final time on the Heights of Weehawken on July 11, 1804.
In addition to being the First Sunday of Lent, Sunday is also World Human Spirit Day. (We've got spirit, yes we do. We've got spirit, how about you?)