NEED FORMULA FOR EXCEL SPREAD?

Ive created a time sheet file and have all the formulas calculated but my question is how can I create a formula the takes the times and give me a certain number. I need this because I need to know the shift diff for certain individuals. for example if someone works from 8 a-5 p I need a "1" if they work in between 4 p-12 a i need a "2" and if they work 12 a-8 a i need a "3"