Most accurate device time?

bob2302 · 1 September at 1:44PM

goodValue said:

I think with DAB the delay comes from buffering the audio. Latency on the internet is typically ~10mS.

In the Android link posted earlier, it gives a value of up to 2.5 seconds for latency on an Android phone, and that is after compensation techniques have been used.

I'm not sure of the relevance of that, it does not apply to the time on a web page.

debitcardmayhem · 1 September at 1:50PM

I don’t have time for this 😎

bob2302 · 1 September at 3:01PM

PHK said:

Anyone with more than one analogue radio in the past will know this is not correct.

The speed of a signal in cabling is less than the speed of light in a vacuum plus you need to factor in the reaction times of various components in the set, the length of cabling and the natural capacitance and inductance of wiring.

It may have already changed with the imminent end of the 1500m transmitter, but the BBC used to generate the pips slightly ahead of the hour, such that the Radio 4 LW pips were exact when they got back to Broadcasting House.

bob2302 · 1 September at 3:07PM

molerat said:

Checked my devices. Laptop was, say, 30 secs, mobile 29 secs and digital radio controlled clock 28 secs. Re synced laptop and it then matched mobile. I will check again in the morning when the clock has had time to re sync.

That's dreadful, mine are all within a fraction of a second of my desktop computer which is running a proper ntp daemon (Chrony).

droopsnoot · 2 September at 9:37AM

This discussion reminds me of the the old saying "A man with a clock always knows the time, a man with two clocks is never quite sure"

Cornucopia · 2 September at 11:44AM

I have a Lidl radio-controlled clock and two NTP internet clocks that I made myself (*).

So, at least two technologies available that provide a permanent to-the-second accuracy. Every other time-keeping device I have (including the car which seems pathologically incapable of setting its clock based on either radio or internet) float around by at least 1 or 2 minutes. (Not enough to be a problem, but enough to notice).

The time.is link above looks accurate for me on my connection. It's less than 1 second apart from my NTP clock.

(*) I think these are also available commercially - Amazon seems to have one.