March 31 is observed as several holidays, but the best-known one is César Chávez Day in the U.S.

Common March 31 holidays

  • César Chávez Day.
  • International Transgender Day of Visibility.
  • World Backup Day.
  • National Crayon Day.
  • Dance Marathon Day.

Quick note

The exact holiday depends on the country or region, because March 31 has both official observances and unofficial “national days.”

If you want, I can narrow it down to your country or tell you the most official holiday for March 31.