You can choose to have recurring plans with no expiration dates (indefinite,) recurring plans with a specific duration or expriation, or let the payer decide when the plan expires when they're checking out. To create a recurring plan with a specific duration:
1) Create a new payment form (or find the form you would like to edit.)
2) Find the Frequency section and choose Recurring from the drop down menu
3) Next, choose Set Recurring Options
4) Choose the recurring period you prefer - Monthly, Quarterly, or Annually
5) In the Duration section, choose Fixed Amount of Time.
6) Enter the number of quarters, months, or years you'd like the recurring plan to last
7) Once you're finished, click the Save & Finish or Save button.