March
This diversity calendar starts with month-long celebrations:

National Women's History Month

Developmental Disabilities Awareness Month

Greek-American Heritage Month

Irish-American Heritage Month

March 1: Maha Shivarati, a Hindu festival celebrated to honor Lord Shiva and the arrival of spring.
March 1: Lailat al Miraj, a Muslim holiday commemorating Muhammad's journey from Mecca to the Farthest Mosque in Jerusalem and beginning the night before at sundown.
March 2: Ash Wednesday, the first day of Lent in the Christian calendar.
March 8: International Women's Day, celebrating women's social, economic, cultural, and political achievements and highlighting women's rights.
March 9: Asian American and Pacific Islander Women's Equal Pay
March 16-17: Purim, a Jewish holiday marking when the Jewish community in Persia was saved from genocide, celbrated by giving charity and feasting.
March 17: St. Patrick's Day, a holiday celebrating the patron saint of Ireland.
March 18: Holi, a Hindu and sikh spring festival celebrating spring and new beginnings with bonfires, bright colors, and feasting.
March 20: Ostara, a holiday celebrating the spring equinox observed by Pagans and Wiccans.
March 20: Norooz, the Persian New Year.
March 20-21: Naw-Ruz, the Baha'I New Year.
March 21: International Day for the Elimination of Racial Discrimination, declared by the United Nations in 1966 to honor the killing of 69 people at a demonstration against South African apartheid.
March 24: All Women's Equal Pay Day
March 25: International Day of Remembrance of the Victims of Slavery and the Transatlantic Slave Trade, declared by the United Nation in 2008 to honor and remember slaves who died.
March 31: International Transgender Day of Visibility