I use a spreadsheet in my medical office for referrals. It includes places to fill in these three areas: date faxed, date of the appointment, date the appointment office notes were received. The problem is that sometimes people don't go to the appointments. I want the 'date of the appointment' box to highlight in yellow if it has been 1 month since the 'date faxed' and no appointment date has been entered. I also want to have the 'date of the appointment' box changed to a red highlight if it has been 6 months since the 'date faxed' and no appointment date has been entered. How would I go about doing this on the Google drive spreadsheet?
Google spreadsheet's conditional formatting is much more limited than Excel. You can only change a cell's color based on its own value, not the value of other cells. So you'll have to add a new column.
Let's say that Column A is the Date Faxed, Column B is Appointment Date.