Find the Date When a Web Page was First Published on the Internet
http://www.labnol.org/internet/search/find-publishing-date-of-web-pages/8410

Teste

There are basically three different dates associated with any "public" web page that’s available on the Internet: 1. The publication date - this is the date when a web page or a website is first uploaded on to a public web server so that human beings and search spiders can find and read that page. 2. The discovery date - this is the date when search engine spiders first discover a web page on the Internet. Given the fact that Google has become so good at crawling fresh content, the date of first-crawl can be the same as the actual publication date (#1). 3. The cache date - this is the date when a web page was last crawled by the search bot. While webmasters can use XML sitemaps to hint search engines that a page on the site has changed, search bots are free to ignore that advice and therefore the cache date may or may not be the same as the last modified date. To give you an example, the publication date of this article is February 25, 2008 (it’s mentioned on the web-page)

inurl:http://www.labnol.org/websites