Have you ever heard of World Juggling Day, Runner’s Selfie Day or Pizza Day?

These are only a few examples of unofficial national holidays celebrated yearly.

While the U.S. only has 11 officially recognized federal holidays, it may seem like a new holiday is celebrated at some capacity every day.

So, where do these unofficial holidays come from and who keeps track of them all?

The Chase Calendar of Events is one of the official reference books that keep track of national holidays, important events and quirky holidays that can populate anyone’s social media feed.

The reference book, operating since 1957, also allows people to submit holiday ideas to celebrate anything from guitars to relaxing.

The company has an online submission form that anyone could fill out to create a holiday.

The submission period usually starts in November and ends on April 15 of the following year to ensure that new holidays will be added to the annual reference book.

After the submission, a team of people researches the idea to see if the holiday already exists and how the creator proposes it will be celebrated alongside other stipulations.

“We try to follow the spirit of our co-founders, Bill and Harrison Chase, because they felt like anyone should be able to create an unofficial holiday,” Holly McGuire, editor in chief of Chase’s Calendar of Events, said.

The company is working on a new submission form before releasing it to the public for this year’s submission period.

McGuire said that the reference book started taking submissions for and publishing quirky holidays after its second year in operation. The U.S. Chamber of Commerce used to keep track of commercial holidays, like American Heart Month, but soon asked the company to take over.

“I would say within the last 10 years, the unofficial holidays have really taken off,” McGuire said. “It’s kind of become a Wild West.”

Aside from unique holidays, the company also keeps track of important days, like when Easter will be for the following year, and anniversaries like the 250th anniversary of the Boston Tea Party, which will take place in 2023.

With over 12,500 entries, the company continues to inform the public and media about important upcoming days and exciting holidays.

“A lot is going on every day of the year and I know that sometimes people make fun of  (the unofficial holidays), but at Chase’s, we just think it’s fun to celebrate lots of different things,” McGuire said.

People interested in getting a copy of the reference book can visit the Chase Calendar of Events website or follow them on Twitter since they occasionally tweet about the important days coming up.

As the end of the year and the holiday season approaches, people can also prepare to celebrate Sandwich Day on Nov. 3 and Saxophone Day on Nov. 6, along with others.