Time Sheet for customer billing purposes

I did my research. Really! But my scenario seems to be slightly out of the box than the other remediations I read. So, here it is:

I have a small field crew that works on a job. They bill each of their hours, per job, per day. OVERTIME is calculated as 1.5 ANY TIME work is conducted between the hours of 1700 thru 0800. Now, that computation is strictly for billing purposes, not the actual employee. I'm pretty certain it requires an IF statement, but as I am merely an EXCEL apprentice myself, the computation eludes me.

PLEASE HELP!

To make things more simple, or, to provide some clarity (even for myself), I will post an example for whomever visits the .xls file and tries to help.

Say Shane comes in at 0600, and leaves at 18:00. Well, that's 12 hours. There is a column for drive time, which in this case is +2 hours. So, we're looking at 0500-19:00. Can't forget that he took lunch which is a net -1 hour. And, can't forget his reporting, so there is a net +1 hour. So I'm back at 05:00-19:00, which for me (because I can add) means: 8 hours of Regular time, 5 hours of OT. Not to say my Tech's can't add, but, the days are hectic and we find ourselves way under billing per job. Thanks again!