NB: The user must have the 'Add activities' and 'Manage assignees' permissions to be able to reschedule/extend a recurring activity. 

NB: Rescheduling results in resetting a recurring activity completely. You will be warned that all occurrences in the current recurrence will be deleted. A reschedule will not affect only occurrences with the start date in the past and with time logs.

You can reschedule a recurring activity at any time.

To reschedule a recurring activity:

1. In Activity Center, select the recurring activity you would like to reschedule OR any of its occurrences.
2. Click the additional options button (  )
3. Click 'Repeat'.
4. Click Reschedule.
   1. 
5. In the Recurrence dialog box that opens:
   1. Set the recurrence pattern in the fields Repeat every and Repeat on.
   2. Set the start date in Starts on (current date by default).
   3. Select the end date of the recurring activity in Ends on (limited by the period of recurrence not exceeding one year), OR
   4.  Set how many copies of the activity will be created in Number of occurrences (max 99).
6. Click 'Reschedule'.