I wanted to know average age of tickets CREATED during each quarter. I noticed the average resolution days measure is based on the resolution date, regardless of when an issue was created.
I was able to create the the measures I needed by modifying the average age of open issues measure from this sample report.
I successfully created reports for Open Issues by Created Period and Closed Issues by Created Period, along with a standard Closed Issues by Resolved Period.
Calculated member formula for Average Age Open
Calculated member formula for Average Age Resolved
I hope this helps someone.