1. Go to Configuration > Staff and resources > Schedules

2. Find one of the active schedules, normally called "Opening hours"

3. Click on the schedule under "Schedule periods"

Change the opening hours by clicking on the schedule under "Weeks".

If you want to have specific opening hours on a specific day, for example christmas, you can add these by clicking on the blue + under "Deviations"

When adding deviations you will see a page where you can:

1. Choose name

2. Choose facility (if needed)

3. Choose the period of this deviation

4. Mark the facility to be completely closed or choose different opening hours for this period

5. Choose which schedules it should apply to within the selected facility. (If you didn't choose a specific facility in step 2, you will be able to see all the schedules.