Welcome to December 16th on the National Day Calendar.

While many traditions uphold the beauty and magic of Christmas some are just plain weird. Behold, the ugly Christmas sweater!

No one is 100 percent sure how this became a holiday thing, but tacky sweaters can trace their popularity back to 1980s TV comedies.

It started on the Cosby Show and became a running joke that sitcom dads wore sweaters that looked like abstract art.

Then in 2002, the city of Vancouver threw an ugly Christmas sweater party that was such a hit, it became an annual event.

Each year, the proceeds from this fashion eyesore are donated to the Make-A-Wish foundation and that’s a truly beautiful thing!

On National Ugly Christmas Sweater Day show your holiday spirit with something fun and hideous.

Here’s the list of all the national days you can celebrate today.