Is there a field for “Approval Date” for Sales Order? Can I use it in a Saved Search?
there is no approval date field in any transactions by default (you can create a custom one and set the date by your approval workflow). There is another option is to use systemnotes – use the join option for systemnotes and use the change date and time for the approval status field, that is look up the time when approval status field value changed from pending approval to approved. I know this is a convoluted way of doing it but 100% sure it would work since you are using the system audit trail.