When you use escalations with working hours you might not get the behavior you expect if you don't pay attention.  Here's an example.  Let's say you have defined working hours as 9AM-5PM Monday-Friday--that's 8 hours a day.  If you set an escalation for 1 day, when will the escalation fire if it is set at 9 AM on Monday?

The casual answer (which I think many people assume) would be 9 AM Tuesday.  But that's not right.  The escalation will fire at 5PM on Wednesday.

What??

It all makes sense once you understand what is happening.  One day has 24 hours, yet working hours are set to 8 hours per day.  So using 8 working hours per day, a 1 day escalation will take 3 - 8 hour days (3x8=24 hours) before it fires.

That will really mess with your head.  Be careful when setting those escalations.