March 31

Context and calendar details

March itself takes its name from Mars, the Roman god of war; in early Roman calendars March was originally the first month of the year. March 31 therefore often functions as a symbolic boundary: it closes the month and the first quarter of the year for many fiscal and administrative calendars. In astrology, most years March 31 falls under the sign of Aries.

Observances and cultural notes

Several modern observances and commemorations occur on March 31. Some are internationally recognized, while others are national or community-based. Examples include:

• International Transgender Day of Visibility — an annual day dedicated to celebrating transgender people and raising awareness of discrimination they face.
• César Chávez Day — observed in parts of the United States to honor the labor leader César Chávez; it is marked by educational and community events in some states.
• World Backup Day — an informal day promoting regular backups of digital data and awareness of data loss risks.

Uses, importance, and notable patterns

As the month and quarter boundary, March 31 is important in accounting, taxation periods for entities with quarter-based schedules, and the timing of seasonal activities in temperate climates. Because some holidays and religious observances are movable (for example, Easter), their dates occasionally coincide with March 31 in certain years.

Historically, specific events fall on March 31 in different years and cultures; encyclopedic lists typically record political anniversaries, notable births and deaths, and milestones in science or the arts tied to this date. When consulting such lists, check reliable chronologies or archival sources for verification.