Easter Monday is a holiday.

Easter Monday is a French public holiday. It started in the Middle Ages. Napoleon Bonaparte’s calendar system still determines when it is celebrated.
The holiday’s origins are ancient, dating back to the Middle Ages. It was established as a public holiday in France. Napoleon Bonaparte created the French calendar. This calendar continues to affect the date of Easter Monday. The holiday is now a significant part of French culture.
Summarized from the sources above. Read the originals for the full story.
Highlights
French Calendar's Napoleonic Roots
The French calendar’s structure still influences the date of Easter Monday.
Medieval Origins of the Holiday
Easter Monday’s holiday began in the Middle Ages.
Napoleon's Calendar Established Holiday
Napoleon Bonaparte created the French calendar that determines Easter Monday.
Public Holiday in France
Easter Monday is now a public holiday in France.
Connection Between Dates
The current calendar system links the date of Easter Monday.