This option is available with a toggle in Modifier groups.

Please verify this again, it only shows the hours within the store open/close and based on pickup/delivery slot. 

This feature is released to production in the new BO, OLO store settings. 

This has been completed. 

Holiday closing schedule is released to production in the new Backoffice UI. 

This function is released to production in our new Backoffice UI.