Unbeknownst to many, every day is a different “national” holiday. From National Tortellini Day to National Create a Vacuum Day, each day celebrates strangely specific people, actions, or objects. Although they are not officially a part of the calendar, most of these “holidays” have interesting origins explaining their peculiarity.

Historically, holidays were determined separately by specific religious events and occasions. Today, a holiday is only official when approved by Congress. In the 1980s, Congress passed numerous absurd holidays until the House of Representatives finally put an end to the frenzy, according to National Public Radio. Unsatisfied people then submitted their unofficial national holidays elsewhere, namely to the book, Chase’s Calendar of Events. According to National Public Radio, this book is considerably large and has over 750 pages. Similarly, a National Day Calendar website founded by Marlo Anderson in 2013 lists national holidays by month and has even made a profit by selling calendars.

While these holidays seem to be the product of silly passions, the unfortunate truth is that most of them were made for advertising purposes. National Pancake Day, for example, was created by IHOP to promote their own restaurants. Similarly, Dunkin’ Donuts has taken advantage of National Coffee Day to increase sales.

Other holidays, however, have more amusing origins. January 3 is National Fruitcake Toss Day and was invented in order to discard undesired fruitcake after Christmas, according to Huffington Post. National Open Umbrellas Day is celebrated every March 13 and was created in spite of the popular superstition that opening umbrellas invites bad luck. Talk Like a Pirate Day, on September 19, was created by two friends who imitated the speech of pirates when they played racquetball.

Blame Someone Else Day is on the first Friday the 13th of every year and was begun by a woman who made excuses all day when her alarm malfunctioned. National Weatherperson’s Day is celebrated every February 5, the birthday of one of the first weatherperson, John Jeffries. National Organ Day coincides with Valentine’s Day on February 14 in the common spirit of giving one’s heart away in the literal sense.

Some particularly bizarre holidays have no known explanations, however. National Microwave Oven Day, National Bubble Wrap Appreciation Day, National Hot Buttered Rum Day, and National Step In a Puddle and Splash Your Friends Day are among many which may always be a mystery. Nonetheless, people celebrate these holidays wholeheartedly and take pride in doing so. When asked about the eccentricity of these unofficial national holidays, Angelina Nguyen (10) laughs and says, “My favorite would probably be National Waffle Day. Some of the days that people make up are so funny.” Creating national holidays is a limitless opportunity to celebrate something new every day.