recurringevent

RecurringEvent, sometimes written as a single token recurringevent in programming contexts, is a construct used in scheduling to represent a series of occurrences that repeat over time rather than a single date. In calendar systems and scheduling APIs, a recurring event is defined by a rule that generates multiple instances from a common start date and time.

Recurrence rules specify frequency (daily, weekly, monthly, yearly), interval, and constraints such as specific weekdays, month days, or patterns like “the second Tuesday of every month.” Many standards use a compact syntax, such as the iCalendar RRULE component, to express these patterns. A recurrence may also specify an end point via until or a total count via count. In practice, systems may store a rule plus a start date and may generate instances on demand or ahead of time.

Implementation considerations include the ability to modify a single instance without changing the whole series, which leads to exceptions. Exceptions are typically stored as EXDATEs or as overrides in some systems. Time zone and daylight saving time changes can affect the exact timestamp of instances. Systems may also support additional dates via RDATE. Handling long-running series can present performance and storage challenges if all instances are expanded eagerly.

Standards and use: The iCalendar RFC 5545 defines RRULE, RDATE, EXDATE for cross-platform compatibility. Recurring events are used for meeting schedules, class timetables, resource booking, and reminders. Complex recurrences can require specialized logic for generation, display, and storage, and broad series may necessitate efficient management strategies.