Does 'show x #of posts' effect indexing

[WebBender]

The was a question on my web forum's support board regarding when one puts in Display Posts from 'x' number of days as the default per forum (30 is default) would GoogleBot and other bots be able to find older posts.

It was something I never really thought about.

Initially, I thought- well, Googlebot is just like a Guest and would only be able to index what is can see.

However, on a forum I operate there are pages indexed that are far older than 30 days. In a random click of pages indexed in Google one result was from November. There are no links to the post.

So, once a page is indexed in google how does Google know to keep it in the index and not drop it?

I'm not sure how recent GoogleBot activity would find messages from back in november. :)

Gbot seems to gooble up forum pages and I'm not complaining- just wondering how older messages remain in the index if all forums are set to show just 30 days of posts.

I use a URL rewrite so that SE's can spider the plain .htm pages on my forums. It works well.

GoogleGuy, I'm glad Google keeps pages it finds in the index, but would like to know if it matters (it seems not) whether we display 30 days, 90 days, or wahtever on our Forums?

TIA

WB