Templates for calculated measures that return the value of an earlier or later period at the same level.
Prior and future period templates are typically used for time period calculations. However, you may use any attribute dimension in a prior or future period calculation.
The order of the members of a level in an attribute dimension is determined by the optional ORDER BY phrase in the definition of the level. If the definition does not specify an order, then the order is based on the key attribute of the level.