A solution for managing dates is provided, in which a recurrence definition that represents a list of dates using a recurrence rule is automatically identified. The recurrence definition may also include a set of exceptions, which account for variations from a recurring pattern in the list of dates. In one embodiment, an efficiency measure is obtained for each of various proposed recurrence definitions, and a recurrence definition that most efficiently represents the list of dates is identified. In one application, an event management (e.g., calendaring) program automatically identifies an efficient recurrence rule for a list of event occurrences.