Active Membership Contract
The billing interval on a membership contract on a customer's account cannot be changed, including the length and when it ends.
If you need to bill a customer on a set date, you can terminate it and resell it for that date or use the freeze functionality to set it to bill on the specific date.
The billing interval can be changed on the membership contract configuration for future sales.
Canceled Membership Contract
If a membership has been canceled, the remaining intervals left on the membership can be reduced but not extended.
In the customer's profile, go to Memberships > ellipsis next to the canceled membership > Cancel renewals.
Enter the number of intervals, confirm the membership end date, and cancel the membership.
If the number is more than the remaining intervals, you will be prompted to enter a smaller number.