Pretend Phone Bill using LEFT and RIGHT

Hi,
I'm trying to construct a phone bill (a pretend one) and basically there's several different rates for things like Weekends, 8pm to 12am, mornings, etc. (I'll explain about those in a moment). I've attempted this program several times to no avail. I do have the basic setup of my program in a .jpg I just need it to determine the rates, if one of you experts could possibly help me that would be great.

My Program:
\1

The Rates:
Weekends (Sat + Sun): $.09
Weekdays before 8pm: $.12
Weekdays after 8pm (8pm - 12am): $.11

When I was trying to do it myself I was just saying if the left of Day 2 characters is S then the rate is .11. And if the Right of time 2 characters is AM then the rate is .12. And then if its 1pm-7:59 (just using left function you wouldn't need to make it be :59) and then that equals .12 also. And then else its just .11 for the rate, but I couldn't quite get the function correct. Can anyone figure this one out for me? Thanks, greatly appreciated.

Does anyone have any idea? I'm basically stumped. I have a feeling it will take Circular Referencing or something... I'm not totally sure... Any help will be appreciated.

Try =IF(WEEKDAY(A2,2)>5,0.09,IF(D2<20/24,0.12,0.11))*E2 in cell F2


However most cheaper weekday calls are often till say 6am so it may need ammending. Also if a call starts at say 7:50 pm and runs till 8:10pm do you wish to calculate it as 2 rates or does it stay at the start rate

It can be done, but the formula is more complicated and there is no point me thinking about it if there is no need

Regards

Dav