April 12 is Equal Pay Day in the United States, when women "celebrate" earning in one year, three months, one week and 5 days what men earned in a single year. It's awful! Even the president thinks so! Still, it's a tragedy that has gone on for a long time, and everyone knows that tragedy plus time equals comedy! Here are some funny tweets (and even some thoughtful ones!) about the annoying persistence of the wage gap: