Suppose A1 has the test date (example 1-Dec-2009 but in any format you like)
And B1 has the date to be tested

Select B1 (and any other cells to have the conditional formatting)
Separately enter these three formulas
=B1-$A$1<=20 ... set fill or font colour to green (B1's date is up to 20
days later than A1's date)
=AND(B1-$A$120,B1-$A$1<=28)... yellow (B1's date is up to 28 days later
than A1's date)
=B1-$A$128 ... red


In all case you could replace A1 by an actual date. For example
=AND(B1-DATE(2001,12,1)20,B1-DATE(2009,12,1)<=28)

I prefer to use DATE rather than DATEVALUE as it avoids the date format (US
vs rest) confusion

best wishes
--
Bernard Liengme
http://people.stfx.ca/bliengme
Microsoft Excel MVP



"Ray" wrote in message
...
I want to be able to make the cell change a color when the date entered
into
the cell has reached one of the three time lines: Green: Dates between
date
in cell and 20 days after, Yellow: Date 21 days after date in cell, and
Red:
Date 28 days after date in cell. I know how to change the color but the
date
formulas are giving me trouble. Any help would be appreciated. Thanks.