National Open An Umbrella Indoors Day is celebrated annually on March 13 in the United States. This day invites individuals to challenge the superstition that opening an umbrella indoors brings bad luck. Superstitions are irrational beliefs that can influence behavior, and this particular day encourages people to test their luck and see how their day unfolds. The origins of this superstition can be traced back to ancient Egypt, where it was believed that opening an umbrella indoors would displease the sun god. Additionally, in 18th century England, the heavy construction of umbrellas made opening them indoors potentially dangerous, leading to the development of the superstition. Participants in this day may open umbrellas indoors to see if they experience any misfortune, thereby engaging with the tradition.