I have a spreadsheet of employees and each row contains name, hire date,
birthdate, address, etc. The field I'm interested in is the expiration date
of their certification.

I am responsible for obtaining annual re-certification for each employee. I
am not allowed to submit the re-certification until 30 days before it
expires. For instance, if the certification expires 10/01/08 and I submitted
today it would be rejected. I would have to wait until 09/01/08 to submit it.

So what I need is a formula that will return all of the records in the
spreadsheet where the expiration date is less than or equal to 30 days from
today. I want it to automatically calculate from today's date without having
to update anything.

Thanks!