Highlighting date cells

hi, i'm working on a worksheet that highlights when maintenance needs to be carried out on various buildings.
i'd like to highlight the date due cells in different colours.

green for "in date"
orange when there is a month to go until maintenance is due
red when the maintenance is due or overdue

the present date is displayed at the top of the sheet with various dates of maintenance due in the cells beneath.

i have tried using excel help but cannot fathom this one.

hope someone can help...its been so long since i've used excel and i am definately rusty!

cheers

Al

use conditional formatting
see here
http://www.contextures.com/xlCondFormat03.html#Expiry
or post a spreadsheet and someone will probably do it for you!!

handy info but can't get my head round it and need it to count in months, not days...
have a look...hopefully i can work out how to add an attachment...

line 6 shows maintenance peridodicy of inspections.

you can see in cell G8 i've had a go at something but failed miserably.

Ideally i'd like the dates to be colour coded as per my initial post but it seems quite complex?

Al

you could use the datedif function
info here
http://www.cpearson.com/excel/datedif.aspx
see attached using conditional formatting it gives red if in past or due now
orange if due within one calender month
green if more

ok, trying the DATEDIF function, as per the link in the previous post.

=DATEDIF(F8,B3,"m")

as per the link i'm getting a #NUM! error. obviously its to do with the "m".

i'm such a f*****t, so close....

AL

Got it, simple really...how do i get -numbers if the date has "passed"?

you cant with that function thats why i used iserror in the conditional format
condition 1 on the premis that if it doesnt give a result it mus be in the past