For a company who has working hours of 8 am to 4 pm. 

From 4 PM to 7 PM, the overtime is 1.25 of the hourly wage. From 7 pm To 7 AM, the overtime is 1.5 of the hourly wage.

For days off (Friday, Saturday), the overtime is 1.5 of the hourly wage

How do I set this up as a rule to automatically calculate based on work entries? Would like if it can be requested/then validated as well so maybe using another module is better?