Ok, so these are actually the same metrics that Google Chrome shows you when you hover over one of the lines in the Network tab of their debugger.  This is how they've named them (re-ordered chronologically and kept original order in numbers):

2. DNS Lookup:  timing.domainLookupEnd - timing.domainLookupStart
3. Connecting:  timing.connectEnd - timing.connectStart
6. Sending:     timing.fetchStart - timing.navigationStart
4. Waiting:     timing.responseStart - timing.requestStart
5. Receiving:   timing.responseEnd - timing.responseStart
1. (not named): timing.loadEventStart - timing.navigationStart

4. Waiting is a bit vague.  Maybe "Server processing Request" or something like that.
1. doesn't show up in the Network tab but it's basically 4. plus the time to load all the resources.  In jquery speak, timing.loadEventStart is the number of milliseconds since 1/1/1970 that $(document).ready handlers would fire.

On Fri, Nov 30, 2012 at 8:55 AM, Dan Andreescu <dandreescu@wikimedia.org> wrote:

        timing.loadEventStart - timing.navigationStart,
        timing.domainLookupEnd - timing.domainLookupStart,
        timing.connectEnd - timing.connectStart,
        timing.responseStart - timing.requestStart,
        timing.responseEnd - timing.responseStart,
        timing.fetchStart - timing.navigationStart

I think we ought to read the specs carefully and experiment a little until we figure out precisely what each of these intervals measures and what sort of things it can usefully indicate. It would be good to come up with descriptive names for each of them.

If you want to give it a shot, you can use this gist to get the data in a way that won't break things on older browsers: https://gist.github.com/4174695


I'll be doing so right now as I think this is very important and useful.


Dan