Everybody knows that opening an umbrella indoors is supposed to be bad luck. But is there any truth behind this age-old superstition? Fortunately for those spending sleepless nights pondering this question, there is actually a wacky holiday dedicated to finding out the truth. The aptly-named Open An Umbrella Indoors Day was invented in 2003 by a man called Thomas Knibb. Knibb allegedly hoped to defy silly superstitions by encouraging people to open their umbrellas indoors and observe the (non-existent) consequences.

The best thing about this bizarre holiday is that anybody can take part. Just follow these four simple steps:

Step 1: Find an umbrella and check that you are, indeed, indoors.
Step 2: Position yourself clear of breakable objects and/or people who value their eyesight.
Step 3: Take a deep breath, grasp the umbrella handle firmly with one hand and open the umbrella with your other hand.
Step 4: Note any bad luck that occurs in the following days or weeks.

Note: People who take part in this holiday do so at their own risk.

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All details taken directly from provider content at http://www.daysoftheyear.com/days/open-an-umbrella-indoors-day/