Result Type: Number
Definition: Returns the number of periods between per and relativeToPer, where these are periods (such as you get from Transaction.Period). It is smart enough not to count an End period in 13 period year (use PeriodtoNum if you want to include the 13th period). If the two arguments are the same, zero is returned.
AgeByPeriod (transaction.period, CurrentPeriod())
returns -1, if transaction.period is equivalent to Jun:2000 and the current period is equivalent to Jul:2000; returns -2 if the current period is Aug:2000, and so on.