Changing stage date

How do I manually update/change a close date. Example: Sales rep moved an opportunity to a “closed won” stage but for reporting, we need that “closed won” to show for the actual month it closed and not when the sales rep closed it out.

Looks like IS places a time stamp on this automatically, but hoping I can override it?

The date of a stage move is a system generated date and cannot be changed. I would say that it would probably help you more to put some workflow management guidelines in place rather than waiting for someone to move the stage after the fact.