GM's Day! is March 4th. It is the day the RPGing community celebrates the hard work our GMs do. Like Mother's Day or Father's Day, it is a day of appreciation. You can pick up a gift for your GM or bake them a cake. Get them a nice card or finish that character background you promised. Or run a game for them! Just make sure you tell them how much you appreciate all the hard work they do running their game for you. Show you support by Liking and Sharing the Facebook page here and be sure to join the Facebook Event here.
If you want to know more about it, you can find where Michael Broadstock and Mark CMG from Creative Mountain Games got it all happening, check here on EN World from 2002.