# Calendar management strategies

The term calendar is used for the set of dates that determine the billing period for a credit cycle. These dates include the due date and cycle closing date. For more information, refer to [Managing due date, cycle closing date, and additional grace periods](https://developers.pismo.io/pismo-docs/docs/managing-grace-period).

The following calendar management strategies are available for use with your programs and accounts.

* **Fixed due date:** Due date is fixed, and the Pismo platform uses it to calculate the cycle closing date. The [Fixed due date calendars](https://developers.pismo.io/pismo-docs/docs/fixed-due-date-calendars) guide explains how to create due date objects for a program and assign them to accounts.
* [Fixed cycle closing date](https://developers.pismo.io/pismo-docs/docs/fixed-cycle-closing-calendar-management-strategy): Cycle closing date is fixed, and the Pismo platform uses it to calculate the due date.