Farshad,

Have you seen http://ntp.isc.org/Support/SelectingOffsiteNTPServers ?

H

keshmiri farshad wrote:

> Hi,
>
> I live in Tehran, Iran. I want to set my computer
> clock with NTP Pool Time Servers. There are too many
> active servers in the world and I set my clock with
> some of them. Whether the nearest server to me, for
> example a time server in Turkey, means the best server
> for me and leads most exact time that I can have? Or
> getting the accurate time with less Round Trip Time is
> related to other parameters for servers? I want to set
> my computer clock with the most accurate time that
> possible.
>

For the most accurate time possible, you would need a direct connection
to an atomic clock! Over the internet, the best you can hope for is to
be within five or ten milliseconds of the correct time.

Servers close to you are usually the best. If you configure ntpd to use
four servers it will select the best of the four.

If you can obtain a GPS timing receiver you may be able to get within a
few microseconds of UTC.