4 Shift Structure A,B,C,D

I am trying to get a working shift structure with a data set. I have the time and date in seperate columns.

Our current shift strucuture is 

A: Monday - Thursday 5AM - 5PM

B: Monday - Thursday 5PM - 5AM (5 hours into Friday morning)

C: Friday - Sunday 5AM - 5PM

😧 Friday - Sunday 5PM - 5AM (5 hours into Monday morning)

I have created a table to reference the day name and the hour and return the shift, but it doesn't seem to be the best option.

Any help is apprecaited.

Thanks!