[ntp:questions] National time standard differences

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Tue Feb 9 13:16:36 UTC 2010

David J Taylor wrote:
> Most likely asymmetrical paths, yes. To answer your implied question, it
> is most /unlikely/ that the USA National Time is 17 milliseconds away
> from Japan National Time, if that's what you were thinking. National
> time differences are likely to be microseconds or less, I believe.

Single-digit ns is more like it:

GPS had ~10ns as their internal target vs US standard time, and the US 
would be within 10 ns from the global UTC paper clock, many years ago.

Today we're almost certainly significantly closer than this.

- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

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