Originally inspired by the National Day of Prayer that religious groups created to draw attention to their beliefs, the National Day of Slayer was thought to be a holiday on June 6, 2006 — that’s 6/6/06 — but now it has grown.
http://www.nationaldayofprayer.org/
Thanks to support and enjoyment around the world, the National Day of Slayer is now the INTER-National Day of Slayer, and it happens every year on June 6 starting at hour six. On this day, metalheads worldwide stop the pointless activities of a boring world and listen to Slayer.
International Day of Slayer is bigger than one nation, or even one band. It’s a celebration of metal music through one of its most articulate spokesbands. It’s also revelry in the spirit that makes metal great. So on June 6, stop everything… and listen to SLAYER!