HELP! I am trying to track the number of times employees have unexcused absences in a 90-day period. I have a spreadsheet where the date of the absence is input. What I need to do is create a formula/code to calculate if an employee has three or more incidents in a 90-day period. If so, I need a visual flag to appear in another cell.

Does anyone have any ideas how to calculate this with the visual flag?