Hello,

Daily sales and purchase reports are just listing with custom (form) filters. The date should work fine. If you go add sale or any other order page with date, form will set the date `now` and if you leave it without submit all the data will be saved in the browser. You came back to add sale page next day, the date will be yesterday's one. There is no other date related issue. If you have any, please do let us know.

The profit and los report is general ledger (Total Sales - Total Purchases), the report page has all the details you need. All the sales number come from database, you can check your database to verify. The daily/monthly sale number won't be changes unless you edit/modify the sales for previous days.

Thank you