Multiple Calendars for Multiple Companies

This is pretty much what we are doing now.  We have groups and each group has it's own fiscal calendar.  I simply join to the fiscal calendars in my tabular model through my regular calendar on the date key field and then access the fiscal parts of the group's calendar by slicing on the Fiscal Calendar name.  This gives me one calendar to work with given a slice of the group table.  It's working okay and I think this is the direction we are going to take.