Problem: after the SLA times calculation, result is a non-working day (Saturday or Sunday). Even though Service Profile clearly states that SLA should be calculated only for Monday-Friday.

Solution: one of the reasons for this to happen can be customizing set in the Service Profile’s basic data. You should go to TCODE CRMD_SERV_SLA and check Service Profile for incorrect SLA calculation. The option you should look for is Variances > Exceptions. You should select value K not on non-working days. This way system will know that SLA should be calculated only for working days, without any exceptions.