ePayments can not be scheduled to occur automatically.
You must use Transactions > Process Credit Cards/Bank Accts to a process a group of credit cards or bank accounts at once. The e-Payment Schedule field (found on each Family's Billing Info tab) allows you to select a time to process credit cards or bank accounts for a group of people. You can learn more about how this works in the Process ePayments for Multiple Families topic.
Learn more in the Process a Single Credit Card or Process a Single Bank Account Draft topics.