Format cells to highlight within time frame for future date?

[story]

Hi, I have a spreadsheet with an Expiration Date column, with dates ranging from some expiring this year to 2021. I need to have dates become yellow when they are less than 3 months from their expiration date and red when they are less than 2 months from expiring.

I know I need to do some conditional formatting, but I'm not quite sure how. I've tried searching, but I only come across how to do it from todays date, but I need it from various future dates.

Any help would be greatly appreciated and if I need to post any more information, please let me know.

Thank you!!

 

[story]

I'm using column D, dates run D8-D61

 

[chesspupil]

I think you are trying to do a predictive strategy... something like how many people will expire within 3 months in the 3rd quarter of next year. You can set the date in a known cell and make that a locked reference. So if A1 is the place you want to make changes you can do =today() or you can enter your own query. all your conditional formatting is still based on the value of $A$1.