Logging workhours and overtime!

Hi!

I am trying to create a log (or report) for how many hours I work every month. I want it to automatically count how many hours I've worked and also when I work more than 6 hours for one day I want it to remove 45 min lunch.
This I have been able to do like following:

A9 = Monday
B9 = 1 (date)
C9 = Worked From (ex. 8:00)
D9 = Worked To (ex. 16:45)
E9 = =IF((((D9-C9)-INT(D9-C9))*24)<=6;(((D9-C9)-INT(D9-C9))*24);(((D9-C9)-INT(D9-C9))*24)-0.75)

BUT! This is the part I can't figure out. Fridays after 18:00 I have 75% extra pay all the way through the night until 7:00 in the morning.
Saturdays I have 50% extra pay until 14:00 from where I get 100% extra pay.
How should the formulas look like for the cells where I get extra pay?

For example if F9 is 50%, G9 is 75% and H9 is 100%.

Please help!
Thanks!