Pivot Table Grouping Problem!

Hi all

Bg: I have an Access database which resembles data from a call center, the main time measures are Open Date, Modified Date and Closed Date.

I'm trying to create a Pivot table which can display the volume of calls that come in by the Open, Modified or Closed dates.

My problem is that I can't use the 'Right Click' Group... option to Group by Year, Month, Week and Day. I can only group by either Week (by itself) or Year, Month and Day.

I had a solution in mind:

- Create a 3 Week columns (Open, Modified and Closed) which I can store my Week values in.

However this would create 3 new fields and I'm afraid this will confuse the end-users even more.

Does anyone have a solution to this?

PS. I have tried creating an OLAP Cube from the wizard but I have a lot of issues with Client Safety errors etc. and with Office 2007 (we are upgrading soon) doesn't have this option available.

Thanks in advance!!!

Can anyone help please?