If you would like to set up the regular closed or day off
Please check following step and set it by iPad.
Settings > Business Settings > + New
Edit name and leave it a blank in Opening Hours
scroll down and mark the day that you want to make it closed regularly
Press the orange button < Business Settings go back to previous page to save your setting. And check if you make the setting successfully.
In the future, when you suddenly want to close a specific date, you may add it into this module.