Highlight Future Expiration Dates

Hi there, 

I am surprised at how hard it is to find out how to highlight future expiration dates, as the dates are 30, 60, 90 days away.  I find the "Format Cells that contain a date occurring" completely useless for this spreadsheet as there is no way to customize the date.  I will do my best to describe what I need to do...

I have a spreadsheet that tracks our teams certifications and when they expire.  

I enter the expiration date into the cell that correlates to the certificate (rows) as well as the employee (column).

The dates entered into the cell can be more than 36 months in the future.

I need the cell to highlight Green if the expiration date is 90-61 days away from todays date

I need the cell to highlight Yellow if the expiration date is 60-31 days away from todays date

I need the cell to highlight Red if the expiration date is 30 days or less from todays date

Any dates more than 91 days away need to remail unfilled.

Please help!  If you know how I'd appreciate your time, or if you know of a great tutorial pop it down and THANK YOU!!!!