Searching For Web Pages Containing A Given Element Type

I am currently developing a simple browser plugin that will collect some data and apply a few style changes to <time> elements. The plugin is working well enough against a few test pages that I have created myself, but we all know that web pages in the wild often stray from the spec, so I would like identify some number of pages that use the <time> element within their markup and validate my plugin against them.

The problem is, <time> tag usage does not seem terribly common to begin with and I would like to validate against a wide variety of pages, including those generated by large, professional development teams (e.g. a Google project page) to tiny blogs and such (those tend to have more ... interesting usages).

So, how do I find pages to use as testing input? Using search engines has proven difficult, since, by design, they are much more concerned with identifying semantic rather than structural information. I suspect that since developers often wish to use real-world data as testing material, there might be a common method that I am unaware of.

Note: This question is specifically about how to find real-world data for software testing purposes, the details (HTML pages with <time> tags) are incidental (it could just as well be pages with <applet> tags), so please provide answers in the more general sense of the question.