Dynamic Content and the Google Update

How does Google index content that is rotating?

[tlhmh1]

Perhaps this is a stupid question, but I've learned from this board that for some people who have sites with content on the homepage that changes everyday, Googlebot might visit them every few days or so.

My homepage displays Topic A on Monday and Thursday, Topic B on Tuesday and Friday, Topic C on Wednesday, Saturday and Sunday, and back to Topic A on Monday and Thursday, etc...

Each Topic, while related, is uniquely different.

My question is this... Is the content on the page at the moment Google updates all the content it uses when determing ones ranking for certain keywords?

In other words, if Google visits my site on Tuesday during the update, will only Topic B be considered when indexing, even though Google visited my homepage every few days for the last month, and could have easily seen Topic A and Topic C?

Finally, if Google ignores Topic A and C during this update, but I really want my site to be listed, first and foremost, for terms related to, say, Topic C, is it considered cloaking to make sure Topic C is served to Google, regardless of the day it visits? Afterall, Topic C IS shown to our users 3 days a week, so its not like we're hiding something.

[WebGuerrilla]

I think you are confusing crawling with the update. The update is the time when a new database is roled out. That data was collected over the previous 2 weeks.

Whatever content was servered to Google during its crawl will show up in the following update.

And yes, setting up a system that always serverd Google topic C would probably fall into the category of cloaking.