Colour coding date cells when one month due

Good Morning

I am compiling a training matrix and quite a novice with Excel so help is much needed.

I want the cell with the expiry date for a training certification to change to red one month before due date.

Sounds simple, but I have no idea....

Thank you
Lisa

check out conditional formatting.

Assuming you've never done this before so her goes, this will highlight days that are 30 days before due.

1 Highlight the Cell requiring the Format
2 Select conditional Format
3 Select "New Rule"
4 Select "Format only cells that contain"
5 Select second drop down box and select "Less than"
6 Select next box to right and type in the following "=today()+30"
7 Select "Format" for fill colour or Font colour
8 OK
9 OK

Thank you

Thank you Forest View, much appreciated.