Dates on Google Sitemaps

A big problem Google is going to have with their new sitemap intiative is the honesty and credibility of the people generating them.

In the early days Google used a date that the server dished up for the file they requested but as databases became common place it would be normal for the file to not change yet the generated page would be totally different so Google was unable to rely on that data.

I’ve already mentioned here how much I liked the technique used at Digitalpoint for making pages appear fresh.

Now, I’m faced with having to eat my words. Because what Shawn does is a trick to make the search engine indexers consider the whole site as fresh and dynamic and that’s ok, I think…

But what now for the Google sitemap if you employ that technique? Which date do you give for that url?

• The date of the last post (because the post is the content); or
• The date of the most recently altered part of the page – the blog heading

Ethically it has to be the post as the blog title isn’t really content. So it was OK to trick Googlebot but not to outright lie?

So, I wonder, how many people will be putting the correct date on their content?
If you comment on this post should I be using the post date or the comment date?
If I change the sidebar content should I use the update date or the main page date?

I think the answers are quite clear but I suspect there will be alot of fraud going on. I wonder how Google will police this and how they will retaliate?