Try this Custom Formula:

=OR(DAY(A1)=4,DAY(A1)=12,DAY(A1)=20,DAY(A1)=28)

HTH,
Elkar


"Jean" wrote:

Hi,

I am trying to limit data entries to only 4 days for a billing cycle of:
4,12,20,28, meaning I can enter a date that it can be 3/4/2006 or 2/12/2005
or 6/28/2007 or 8/20/2010 (just limit days in a date to these 4 days, month
and year can be any month and any year),

Help please :)

Thanks a lot!