to long if argument
 

I have got a problem. My if statement gets to long. The problem is this:
I have to check if some requirement fulfilled. Lets say this value is in A1
and needs to be larger than X. If A1 is smaller than X the anwser is 0.
If A1 is larger than X it has to calculete the extra payment I get over my
working hours. These are as follows: the hours/minutes I work between 20:00
and 21:00 are worth 1/3 of my wage per hour extra. Every hour/minute I work
later than 21:00 I get 1/2 of my wage per hour extra.
I made colums of my start and end time. Four situations can occu
start end
<2000 2100
<2000 <2100
2000 2100
2000 <2100

I want to make one statement that checks if I have the right on extra
payment (A1 is larger than X) and calculates the hours of extra payment. Lest
say I start at 2030 and end at 2200 it has to give back 10 minutes + 30
minutes = 40 minutes = 1/3.
Can anyone help my make this statement short enough so excel can calculate it?

Carnelain