### Instruction:
Explain what is April Fools' Day?

### Response:
- In the Western history, April Fools’ Day occurs on April 1 every year. It has been celebrated for more than 400 years
- The exact origins of the Day remains a mystery, though many historians attribute the origin of April Fool's Day to medieval festivals during spring
- The traditions of the Day include playing pranks on others or telling audience jokes followed by yelling "April Fools" at the end to reveal to the audience that they were tricked