Club hours are continuous. There is not an option to divide your business hours into two shifts. However, the business hours set in club information are not seen by public - this is internal information used to create a time parameter for assigning tasks in your club. Therefore although you may not be open midday having your business hours set in a continuous block including these closed hours should not affect operations.
To modify your business hours go to the "Club" menu and select "Information". Choose the "Schedule" tab.