I have a date field in my PWA Projects. I would like to use that date in a workflow to calculate another stage's due date. My thinking is to calculate a new date from the Project Data/Existing date field.
I am using Sharepoint Designer 2013, and when I try to calculate the new date, I add the calculate Action, and choose a value, select Project Data, and choose the Existing Date, but then OK grays out and I cannot use that value as part of the calculation.