The calendar is a game mechanic in The Sims 4: Seasons that allows players to set dates for planned social events. The calendar also showcases the work and school schedules of household Sims, birthdays, seasons, holidays and weather. Social events cannot be planned more than two weeks in advance in the calendar.
The duration of a season can be set to 1, 2 or 4 weeks. The default length is 1 week. The first day of the week will always be Sunday.