A day-end closing is irreversible and can only be carried out once per calendar day.
The day-end closing literally ends the business day. It’s the final confirmation that any business transaction of the current day has been performed and that no changes shall be possible any more.
As soon as the day-end closing is carried out the end of day report is generated and all POS functions that create a business transactions (e.g. checkout, refund, cash withdrawal or cash deposit) are deactivated until the next calendar day breaks down.
If you’ve made a mistake while closing the day you won’t be able to make a corrective transaction up until the next calendar day. In order to comply with tax and accounting requirements the incorrect end of day report remains unaltered. Any (corrective) transaction is always part of the end of day report report it has been carried out.
In such cases it’s best to have a written explanation prepared before any tax audit. For example, you could add a note to your documents such as ‘Operating error while carrying out the day-end closing on 06/08/2018’. As a basic principle you should make sure, e.g. by appropriate job instructions, that these kind of mistakes are prevented, and that each day-end closing on any business day is carried out carefully.