Just wondering whether JavaScript execution i.e. for DOM Manipulation is taken into account by Tools like http://tools.pingdom.com/, Google Analytics that calculate a Web pages Load Time obviously there is a distinction between Download Time & Load Time? Does Load time include when JS has finished executing?
Good question! The short answer is no.
JavaScript "load time" is dependent on complexity, latency to fetch files (CDNs, etc.), and other browser-dependent factors.
A tool like Google Analytics receives data about the page (through tracking pixels), but isn't the same as a bonafide web browser.
A tool like Pingdom or Pingometer which monitors a site either does a HEAD or GET request to the page.
In the case of a HEAD request, no code is downloaded or executed -- only headers.
In the case of a GET request, code is actually downloaded (and a factor for load time) but not executed.