When do I check in and out at the campsite?

This depends on your campsite ticket type. 

If you've purchased a 5 night campsite ticket, the check-in and check-out times are as follows:

Check in:
Wednesday 31 of July 14:00 - 23:00

Check out:
Monday 5 of August at 12:00 (noon) at the latest

If you've purchased a 4 night campsite ticket, the check-in and check-out times are as follows:

Check in:
Thursday 1 of August 14:00 - 23:00

Check out:
Monday 5 of August at 12:00 (noon) at the latest