Do I also have to set the “Allowed from time” and “Allowed until time”?
I now set this to 00:00 until 23:59 but theoretically this means the guest does not have access for 1 minute.
What do I need these values to be to allow full day access between the “Allowed from date” and “Allowed until date”?
No, you don’t need to fill the time values.
Just keep them at 00:00 and it’ll work the whole day.
With those fields you are able to additionally restrict codes on top of the overall date.
e.g. you can create a code that is valid from now till in two weeks but with the time values you may restrict them to only be allowed from 6am till 10pm every day.