[ntp:questions] Re: Freeware for NTP time synchronization under Windows?

David Woolley david at djwhome.demon.co.uk
Mon Oct 18 20:17:25 UTC 2004

In article <MPG.1bdd1a06cc169f4b9896df at news.individual.net>,
"Chaos Master <spammers.****@spam.com.INVALID>" <> wrote:

> I am looking for a freeware Windows program to synchronize PC' clock over the 
> Internet, using the NTP (Network Time Protocol) protocol

What do you mean by Windows?  For any Windows system bought new in the
last two or three years, you should use the reference NTP implementation,
which is, I believe, the only NTP implementation - all the others are,
at best, SNTP.  (If you don't mind a broken SNTP for Windows XP, Microsoft
supply one built in - net time/sntp.)

All products branded as Windows NT, Windows 2000, or Windows XP are NT
family systems and will run the full software.

I think a lot of the replies that you are getting are from people who
are used to answering this question for Windows 3.1 through Windows ME.
At least one of the proposals doesn't even make use of NTP servers 
(although, as noted below, you may not be able to benefit from their use).

> Q: Do you know of any good program for time synchronization using the NTP 

As far as I know, the reference implementation is the only one that implements
NTP.  I don't believe there are are any NTP implementations (only SNTP) for
DOS derived Windows (3.1, 95, 98, and ME).

> protocol? I'd like to synchronize time, say, once I day.

NTP isn't really suitable for this, it uses adaptive polling intervals,
but these don't normally exceed 1024 seconds.  You will need a program
that calculates and applies corrections to the clock frequency for even
SNTP to be worthwhile with a 24 poll period, as many PCs will drift
more than a second in this time.  Without frequency correction, you will
probably find it just as accurate to use the Date headers on your ISP's
web pages as to use a protocol which is capable of making millisecond
(over dialup) accuracy measurements.

As such, why are you specifying NTP?  My guess is that you don't really
want NTP.

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