1December

1 December, written as 1 December in many date formats, is the first day of December and the twelfth month of the Gregorian calendar. In a common year it is the 335th day of the year, and in a leap year it is the 336th. The name December derives from the Latin decem, meaning ten, a holdover from its original position as the tenth month in the early Roman calendar.

Observances and significance commonly associated with the date include World AIDS Day, observed globally on December 1 to raise awareness of HIV/AIDS and to honor those affected. In meteorological terms, December 1 marks the beginning of winter in the Northern Hemisphere for statistical purposes, with winter running December 1 to February 28 or 29, depending on the year. The date also falls within the period leading into the winter holiday season in many cultures, and Advent in Christian liturgy may begin in late November or December depending on the year.

Historical notes of December 1 include notable events such as Rosa Parks’ refusal to surrender her seat on a Montgomery, Alabama bus on December 1, 1955, which helped spark the Montgomery Bus Boycott and became a turning point in the American Civil Rights Movement. The day is otherwise associated with various regional and cultural observances, depending on local customs and calendars.

See also: December; calendar months; World AIDS Day.