Events can be made to repeat in various ways. Many events repeat in certain frequently used ways. For example, the "Monthly" recurrence types make the selected item repeat each month and the "Weekly" recurrence type makes the selected item repeat each week. These can be made to represent events that repeat in complex ways: for example, an item that occurs on the third Friday of each month, or an item that occurs on Monday, Wednesday, and Friday every week.
You can also restrict how long an event repeats by selecting the end date or a recurrence count for the event's recurrence.
Normally, a modification to a repeating event applies to all occurrences of that event. A single occurrence of a repeating event can be modified by editing the occurrence, removing its recurrence information, and then choosing the "Save as New" option from the Repeat menu. The selected occurrence can now be modified independently of the other occurences.