Working Hours
Your Profile's Timing tab controls the boundaries of your availability: daily working hours, your lunch-break window, and your weekly day off. This has been confirmed to feed directly into the Calendar's slot grid — for example, Sunday is correctly excluded as a bookable day, and the configured lunch-break window is correctly excluded from bookable time slots.
Keep your Timing settings up to date — any change there is reflected in what guests can book, without any extra step on your part.