March 21st is the 80th day in the Gregorian calendar; it also marks the anniversary of third—and finally successful—civil rights march led by Dr. Martin Luther King, Jr. and the founding of Twitter. Famous March 21st birthdays include Matthew Broderick, Rosie O'Donnell, and Mark Waid. March 21st also marks International Day of Forests, National Common Courtesy Day, national Fragrance Day, National French Bread Day, National Kick Butts Day, World Down Syndrome Day, and World Poetry Day.

We have 7 holidays listed for March 21.