Re: 'Age' for webpages

Aryeh Gregor <[email protected]> Mon, 7 Jun 2010 16:09:30 -0400
Newsgroups gmane.comp.web.html.general
Message-ID <[email protected]>
On Mon, Jun 7, 2010 at 2:11 AM, Merin Tresa Willy <[email protected]> wrote:
> What about dynamic HTML pages? Is there any mechanism for retrieving the age
> of their contents?

Both Last-Modified and <time pubdate> can be used by dynamic HTML
pages.  If a page doesn't use either of those, there's no way to tell
except guessing.  Google guesses how old pages are based on their
contents to allow filtering by date, for example, but it's wrong
sometimes.

On Mon, Jun 7, 2010 at 3:27 AM, David Woolley
<[email protected]> wrote:
> Competently produced dynamic web content (not just HTML) has a dynamically
> generated Last-Modified header.

Last-Modified headers are not required by HTTP.  They're often
meaningless on dynamic pages, where some parts of the page might
change every few minutes, and competent authors omit them when they
don't make sense.