I'm on a life-long mission, that I'm not really putting much effort into, to find out who decides what day is "National ___________ Day" on the internet. Generally, they're really stupid, but this is one we can all get behind.
So look around you, pick out a co-worker that consitently annoys you and give them a nice, good slap. Then try explaining to HR that "It's an internet holiday, though" and see how that sticks. And if you're looking around, thinking "nobody here really seems annoying enough to slap", then you're the one everyone wants to slap.
Have a great day. Enjoy this video of a Russian Slap Competition.