The First of April, some do say
Is set apart for All Fools Day;
But why the people call it so,
Not I, nor they themselves do know.
April 1st is one day of the year when people from western cultures traditionally play tricks on each other. Today with the Internet the custom is spreading worldwide. The origin of this custom is unclear.  
A giddy spurt of practical joking seems to have coincided with the coming of spring since the time of the Ancient Romans and Celts, who celebrated a festival of mischief-making. The first mentions of an All Fool's Day (as it was formerly called) came in Europe in the Middle Ages.
- ↑ April Fools Day
- ↑ April Fools' Day: Origin and History
- ↑ Why is April 1 a day to celebrate foolishness?
- ↑ Is April Fools' Day Dying?