I need to create an excel where I can only track the days’ employees c

I need to create an excel where I can only track the days' employees call off work. They are only allowed to call off 3 times within any 30 day period. Need formulas in place to change the fields to yellow when they are 2 days off within 30 day period and red when they are 3 days off within a 30 day period. 

1. A column for employee names

2. Only record dates of call-offs (not the whole calendar) 

3. Employee Name field to change color to yellow when 2 call-off dates are within a 30-day period

4. Employee Name field to change color to red when 3 call-off dates are within a 30-day period