[ntp:questions] how long does it take ntpd to sync up

[Richard B. Gilbert]

On 8/27/2011 12:49 PM, C BlacK wrote:
> I read somewhere that it takes an ntpd 24 hours to truly sync up to a stratum 2 master.
>
> Is this true?
>
> Thanks
>
> Chip

It's nowhere near that bad!

 From a cold start, it will take about thirty minutes to get a 
reasonable approximation of the correct time.  NTPD will need about
ten hours to achieve the maximum accuracy that it's capable of.  If
you are serious about having the correct time, you run NTP 24x365.

If you want to run from 9:00 AM to 5:00 PM *only*, NTP is a poor choice 
for the job.  There is a tool called, I believe, CHRONY, which works 
much faster.  You pay for the speed with somewhat reduced accuracy!
This is usually not a problem unless you care about the microseconds.