Calculation is different for past, current and future

[jage]

Hi,

Any ideas on how to build a calculation based on relative time in PowerPlay? There are 2 or 3 calculations I eventually need to appear on one line.

I have an Open to Buy calculation that should be:
0 if it is applied to a past month,
use current inventory in formula if current month
use planned inventory in formula if future months.

Any help would be greatly appreciated. Should I be looking at calculating some measure in Transformer instead?

Thanks