Each SLA Item is related to "Business Hours" (Customer Service Schedule) where we can specify the Weekly Schedule.

This schedule can be related to a Holiday Schedule where we can define full non-working days.

Our idea is to add an option for half-day and specify the working hours for half days.

I imagine it as follows:

1. In the "Customer Service Schedule", if the "Holiday Schedule" field has the value "Observe" then an option to define the schedule for half-day will be visible in addition to the weekdays.
2. In the "Holiday Schedule" entity, there will be a new indication of whether it is a full day or a half-day.
3. The SLA calculation will work according to the half-day schedule if the indication shows a half-day.