Looking for "page too old" script

I have a tsch script that does some things, manipulates and image and such
and posts it on a web site.  Occasionally, I have found a bug or two where
the image stops updating.  I don't know this until it is too late.  Is there
any sort of technique or custom script that will poll a website and see if
something is to old?  I'm at a bit of a loss as to how to correctly indicate
a problem and hoping there is something I can start from already.

Thanks in advance!

Josh Luthman
Office: XXX-XXX-XXXX
Direct: XXX-XXX-XXXX
XXXX Wayne St
Suite XXXX
Troy, OH XXXXX