Calculate rate of Pay

Hope someone can assist.

Looking for a formula that will calculate a different rate of pay based on time employee starts and finishes work.

Two time rates of pay;

8am/8pm - rate of pay 1
8pm/8am - rate of pay 2

I have attached a screen shot of the spreadsheet.

Effectively I just need a formula to look at times in the START and END columns and calculate the appropriate formulas in the RATE 1 and RATE 2 columns.

Thanks in advance.