I have a feeling there might be a fancy way of doing this I am overthinking.
In call director - call flow - we have a number that on hours ring the desk, off hours ring an on call number.
The set schedule can be done per day of the week, and holiday entries, but anyway that we can set it so that it follows a forward location for entire week and rotates through 5 different numbers.
So week 1 would go to person A, Week 2 go to person B, week 3 person C, Week 4 person D, week 5, person E, then week 6 go back to Person A on week 1?