Yes, when creating a membership, you can choose whether the price of the subscription should decrease gradually per day throughout the membership period or if there should be a fixed price. With the latter pricing model, you can optionally choose a number of days up to the end of the membership period that should be completely free. Monthly memberships cannot be graduated. The graduation occurs on a daily basis and cannot be done, for example, on a weekly or monthly basis.

To activate the feature of gradually decreasing membership fees throughout the membership period, you must enable 'Gradually adjust the payment' under 'Payment' when creating a membership, as shown here: