Calendars are what allow the software to track and report data at different levels of aggregation. An example is where you enter data on a monthly basis, but can choose to view this data rolled up to quarterly and yearly levels.
Specifically, there are two ways that Calendars are used:
1. Viewing snapshots of data: See score roll-ups and data aggregations for various summary periods.
2. Defining a measure’s update frequency: When you create a new measure, you pick a calendar to
define how often it is updated.
Calendars are utilized by all users, but can only be created and maintained by users who have the appropriate "Modify Calendars" permission. "Standard" calendars (ex: Weekly, Monthly, Quarterly, Yearly) can be created in a matter of clicks. Additionally, "Custom" calendars (ex: Fiscal Quarterly, Fiscal Yearly, etc.) - specialized calendars relevant to your specific organization - can be created and its individual calendar periods defined.
Each calendar contains a set of periods that span from a start date to an end date. At any time an application administrator can generate additional calendar periods to "extend" these calendars further into the future and the past.