In 'Settings/Users/Access management' enable the right: 'Transfer a sale on a past day'.
In 'Reports/End-of-day' you will find a new button (at the bottom of the page) 'Transfer a sale on a past day', where you can select a sale and the target day for the transfer.
The target day should not be closed.
The sale will keep its transaction/closing dates but will be timestamped on the target day for all reports.
You cannot transfer a sale on a day before the date you switch your account in production mode.