A computer-implemented method of processing recurring events within personal information management (PIM) clients can include executing a plug-in component within a PIM client. The method can include receiving, within the PIM client, an event update including a recurring event identifier that is natively understood by the PIM client and supplemental recurrence data not natively understood by the PIM client. The method further can include, responsive to the plug-in component detecting the supplemental recurrence data and a user input executing the event update, the plug-in component can locate a recurring event corresponding to the recurring event identifier. The method can include the plug-in component updating the recurring event according, at least in part, to the supplemental recurrence data, and storing the recurring event within the PIM client.