Why does my cashier report for today show payments with transaction dates of previous dates?

When processing payments on invoices the user gets the opportunity to change the posting date and time manually. This is designed mainly for payment types such as bank transfers as these may have been received before the day we are posting the payment.

For example, a user could process a payment today, but tell Elina the date they were received where the previous month, therefore these payments will show up on the days Cashier report with these past dates.