Happy National Martini Day! And Happy National Watch Day! And Happy National Garfield the Cat Day! Yes, June 19th is all of those things. Seems like a lot right? At this point, every day is a celebration of multiple "holidays."

With each one, I find myself wondering "HOW did this become a national day? Who even decides these things?" As it turns out, it's actually pretty easy to create a National Day.

There's no one person who does it – although "Official Day Declarer" seems like a cool job title. In fact, anyone can declare a day. The challenge is getting it recognized. Most aren't formally recognized by the government, but some are. For the most part, it's all about promotion.

There are a few "authorities" on the matter though. Chase's Calendar is one of them; it's a big book of days that's been around since 1957. Get your day in there, and it's pretty official.

You can also register your day at NationalDayCalendar.com. If they recognize it, press releases and media alerts go out.

So there you have it. Literally anyone can make up a national day. What would you declare a holiday? Let us know in the comments!