Hi @JPSS ,
There is no OOTB field to capture Approval date.
As a Workaround :
I think you're only option for existing requests would be to report on the approval table and look at the last updated date, which would presumably be when the approval or rejection happened.
A more long term solution would be to add a field to your request/item called approval date and populate it with a business rule when the approval changes to approved. This would be similar to the way the resolved and closed fields work on the incident table if you need an example.
