Glossary

All-day event

An event tied to a date rather than clock times, encoded as a floating date with an exclusive end.

All-day events (picture day, a holiday, a tournament weekend) carry dates, not times. In iCalendar they are encoded as DATE values, and the end date is exclusive: a one-day event on the 21st ends on the 22nd.

The floating encoding keeps the event on the same calendar date everywhere; a birthday should not shift to the previous evening for someone in another timezone, the way a timed event correctly would.