Scanning times and the validity of tickets can be adjusted in the pool. A pool (and the tickets attached to this pool) is - by default - valid the entire duration of your event. The settings are automatically copied from the start and end times that you have given to your event.
It is possible to change the validity of a pool (and all the attached tickets) to a specific time/moment. This is applicable when you sell tickets with different time slots within the same event. If you wish to sell tickets with different validity, you will have to create different pools first. Read more about that here.
The event that the image above comes from, starts at 19:00 and ends 23:30. After 22:00 the venue expands the capacity. The venue wants to sell 30 extra tickets that give entrance after 22:00.
If you created your 'pools' and click on one, you can choose 'Edit'. Here you can give a specific pool its own validity by adjusting the 'from' and/or 'until' times. This 'Late Entrance' pool is now valid from 22:00 and ends the regular end time.
The QR code of a ticket goes live 3 hours before the start of an event. Yet, when a visitor shows up at the event at 19:00 the system will recognise this ticket as 'unvalid', because it will only be scannable from 22:00 onwards.