Query Builder Criteria Logic for getting last month

Hi,

It's that time of year again when 1-1=0.

I use the Get_Month - 1 calculation to capture the work items created last month.

Problem is in January the month = 1

For some reason 1 minus 1 does not equal 12...

Has anyone a better way to get a criteria for 'last month'?

This goes into a Cognos report, so I'm not able to use the 'last month' attributes when running the report with Report Builder