Time issue

Ok,
I'm having a problem with time.

Lets says:

Mon Tue Wed Thurs Fri Total hrs
8 am 3 pm no work NW NW 5 pm- 3am -number

On my total hours I get a minus total number. the problem is in the calculation on Fri. When it goes on to the next day my hours doesn't come out right.

Here is my file.