Hi, I need help.

I need to do a new calculated member in a cube. This calculated member is named as ITD (Interannual-To-Date) and I don´t how to calculated. It must be something similar to PeriodsToDate. For example, if today is January 18 (2007) I would like to know how many cars had been sold since January 18 (2006) to today. Any idea?

Thank U