The maximum duration allowed for a recurring series is 12 months from the current date (the date on which you are scheduling the series). For example, if your current date is April 1, 2011 then you can schedule the recurring series anytime between April 1, 2011 and March 31, 2012.
Note: We calculate 12 months from the current date of scheduling and not the start date of the recurring series. We suggest that you plan and schedule accordingly.