IMO the easiest way to address such tasks is to use a running counter for the period field. This could be done with autonumber() within the master-calendar, like:
load *, autonumber(Year & Q) as RunningQ;
load *, ceil(Month / 3) as Q;
load *, year(Date) as Year, month(Date) as Month;
load date(from - 1 + recno()) as Date autogerate bis- from;
Similar stuff might be also done against YearMonth or YearWeek. Each needed period-field should be created there - in each case as numeric and if needed also as strings or dual() values. The numeric ones might not be shown anywhere but they are needed to calculate/compare anything against each other.
Beside this you could also create a working counter with something like this:
Year * 4 + Quarter as RunningQ
- Marcus
