The Ides of March literally refers to the middle day or March 15. A long time ago people celebrated this day as the change to the new year. They also used this day to settle debts. Then Julius Caesar became the emperor of Rome. He changed the date of the new year and took power to himself. Then on this auspicious day, Brutus assassinated Caesar.
Shakespeare took this story of Caesar and turned it into a play. In the play, a soothsayer warns Caesar to beware of the ides of March. Caesar ignores it and of course, dies that day. From this play, we received this famous warning.
Is there any credence to the warning? Throughout history, other disasters have occurred on this day including assassinations, wrecks, and more. Still, the gloominess of the day probably has no more merit to it than Friday the 13th. If we think something bad will happen, then we will see something bad happen. Whatever your belief, beware of the ides of March.