MY understanding of the issue confirms that you would basically need a js implementation of ntp in order for any of this to work.
That's why I laughed when Time.is tried to tell me that my clock was off by 1.8 seconds. Barring the sentence above, it just has no way of determining that.
All things considered it is not such a bad estimate of the time. It looks like it makes it queries the local clock three times to get an estimation of the clock deltas and network delay . Why do you think 1.8 seconds is wrong? What is your ntpq billboard?
It just seemed like it was claiming a lot of precision that, from my own experience of javascript, browsers and network latency, seemed a bit over the top. (Granted, on the order of magnitude of seconds, I'll accept that. Less than 100 ms and I grow suspicious).
That's why I laughed when Time.is tried to tell me that my clock was off by 1.8 seconds. Barring the sentence above, it just has no way of determining that.