All fools day also known as April fool's day is celebrated on April 1st every year. The origin of this day is uncertain, while some celebrate it as the change in the seasons, while others believe it stems from the adoption of a new calendar.The April Fool's Day is said to have originated in Europe but its not limited to Western World as April fools day or all fool's day is celebrated all across the globe.
While the precise roots of April Fools days is still not sure by the Historians but it is strongly believed that it began after the change of calendar from Julian to the Gregorian one.
According to the history, Pope Gregory XIII started ruling the new calendar which began from January 1 in 1952 instead of the hitherto celebration of new year in the end of March.
The change in the annual calendar was brought to practise fist by the France. After the change in the annual calendar large number of people all across Europe continued with the Julian calendar. This change resulted that those people who adopted the new calendar started referring the ones who refused to change as ‘fools’, by marking the beginning of a tradition which we all know and celebrate it as April fool's day.