Is there a standardized (meta?) tag for the date of a website?

Question

One thing that search engines really suck with is the date when a website was created. You know the problem: You search for some CSS or JavaScript problem and Google returns

Answer 1

You could try RDFa (or Microformats) as James and hangy have suggested, Google supports them through a feature called Rich Snippets. Use the Rich Snippets Testing Tool to see how it's working - for example it does pick up the dtreviewed and the rating from one of my blog posts which is marked up with hreview.