Workspace administrators can create and manage time ranges in the Time Ranges tab of the Time pane. Access Time from the Model settings bar on the left-hand side of your model.
When naming a time range, you can follow the guidance in Name conventions.
The Time range name is visible to users when they access Pivot.
The length of a time range is set in fiscal years. The Start Period is the first year in the time range, so a time range that starts in FY2018 with a length of 1 year will span FY2018 only. You can select any year within the system constraints (1981 to 2078) as the start period. If the start period is FY1981, the time range can have a maximum of 98 years; but only one year if the start period is FY2078.