It is unknown who invented this holiday. There have been suggestions made that in the United States it is meant to give taxpayers a relaxation day after the tax deadline is over.
Pajamas are still part of a normal outfit worn by both men and women during the day in many parts of the Middle East and South Asia. However, most people wear them to bed. Also know as pajams, payjamas, or jammies. They are usually loose-fitting and comfortable.
The word pajama comes from the Persian word, payjameh which means leg-garment.
So, this April 16th, kick back and wear pajamas to work that day!