For using an Escalation you can perform, execute a transition and then the transition.

In this case, the transition "Release" will be triggered after one work day.
For some automatically performed Items, the timing is inappropriate. To perfom it on a specific time would be better.
To improve the adjust settings, would help to use them more often.
An other way would be, to have an item with date and time, and the escalation would be triggered for this specific time.
Only select days, is inaccurate. You never know, when it will happen.