[ntp:questions] Can or should the NTP protocol eventually serve timezone data?

Rich Wales richw at richw.org
Wed Jun 17 21:40:13 UTC 2009

Richard B. Gilbert wrote:

> I have a couple of "radio controlled" digital clocks and a
> wrist watch that do it automagically.  The VLF broadcast from
> WWVB provides the necessary info.

Yes, but all the WWVB broadcast says about DST is whether it is
in effect or not, or about to start or end, according to the
rules currently in effect in the USA.  And all your digital
clocks know is which of the four continental-US time zones they
are in, and whether or not DST is ever observed locally at all.

This is wholly inadequate for the worldwide summer time situation.
Even if WWVB could be received in other parts of the world, its
DST info would be unusable, because it wouldn't be able to take
into account the different rules for when DST starts and ends in
different parts of the world.

In order for me to know if I should follow DST info offered to
me by an NTP server, I would need to know where that server is
and which locality's DST rules it is following.

In my view, it makes far more sense for NTP to keep hands off the
whole DST question and confine itself to time-zone-independent
issues (such as UTC, leap seconds, and TAI offset).

Rich Wales  /  richw at richw.org  /  richw at stanford.edu
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