File Date + Googlebot

Greetings,
A question... Does Googlebot go by filedate or size of file if it is deciding that a file has changed?

Curious... Becuase I use lot of server side includes and I have updated my design. I would like Google to recognize that these files have changed. I have updated the include file but not the files they are included in. This would mean only the include files would have updated file dates.

Does it hurt to go and do a "touch" on all of the files to update their date?

Thanks for the help.

 

As with most questions about Google, the only honest answer to this questions is "No one knows for certain."

However, this it how is seems to work... to me... today...

Google checks for a response which is not an HTTP 304 "Not Modified" response.

Depending upon how your web server works, this is the "date check".

If Google does not receive a 304, it puts the page through its page crunching engine. This includes the mysterious "duplicate page" checker and all of Google's other gooey nastiness.

It can't hurt to touch all of your file dates -- except that your web server will use an incrementally higher amount of bandwidth for a brief period of time because 304 messages will most likely not be sent to either crawlers or normal web users.

In my experience, Google will update the pages without touching the file dates. I have tested this by running a short PERL script which appends the system date to the footer of each page. The dates on the otherwise static pages do change in the Google database.

 

perhaps I'm a bit slow, but...

let's say you have a PHP file that runs off of a database and generates up to date content via that. if you add things to the database- but don't change the php file- it wouldn't register as having been changed, right?

... but google still picks up that they're changed. it seems that way, anyhow.