It's possible to set up time schedules of when devices no longer should be be able to use the internet.
This is done by navigating to Parental control, and then setting up the rules.
It's not necessary to delete the rule if you wish to disable it. This can be easily done with the toggle under 'Enabled' column.
It's important to note that during the start and stop time, the device will loose all connectivity. In the above example, the internet would stop working for the device at 00:00 (12 AM) every Saturday, and start working again on Monday at 00:00 (12 AM).