How to access actual start date of work item via OSLC (agile template)?

Hi everybody,

We are using the agile template and I try to extract the actual start and end date of finished work items from RTC. Using a query I can show the start date, but it always shows "None" even for already started or closed work items. Using OSLC to access the work items I can't even find a start date in the work item directly. I found the plannedStartDate via the schedule feature, but that is set to the start of the iteration for all work items (and not to the actual date when the state moved from new to in progress). Does anybody know how to find out the "real" start date (moment when the work item state moved away from new)?

Some background: I try to calculate the cycle time (time from start working on the work item till finishing the work item). I found a predefined queries in JRS, but it only gave me the overall average cycle time. I need the individual cycle times of each work item of a given period to be able to predict future end dates like Daniel Vacanti suggests in his book "Actionable Agile Metrics for Predictability"

Thank you and kind regards,
Jochen Widmaier