April 1: It's April Fool's Day, you fool!
April 3-10: Happy Passover, Jewish adherents!
April 5: Happy Easter, Christian adherents!
April 6: Happy birthday, borgo!
April 7: Happy birthday, Tem42!
April 18: Shop offline while you still can: it's Record Store Day!
April 20: It's, uh, 4:20 Day for our observant pot-heads and/or medical marijuana patients!
April 22: It's Earth Day, fellow earthlings!
April 24: Happy birthday, Rancid_Pickle!
April 24: It's Arbor Day, Charlie Brown!
If you have something to add to the monthly news, /msg Tem42.