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

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Fri Jun 19 05:46:49 UTC 2009

In article <Zu2dneTYfMCP4aTXnZ2dnUVZ_hOdnZ2d at giganews.com>,
 "Richard B. Gilbert" <rgilbert88 at comcast.net> writes:
>Rob wrote:
>> Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
>>> Rob wrote:
>>>> Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
>>>>> Rob wrote:
>>>>>> Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
>>>>>>> I believe that the O/S vendors supply a file with timezone data.  If you 
>>>>>>> have support, you can even get updates from the vendor.  Since I can't 
>>>>>>> afford support (I'm retired and a hobbyist) I have to do it by hand.
>>>>>> As Jan Ceuleers also pointed out, the problem is not at all limited
>>>>>> to operating systems.  Any device that obtains time using NTP and wants
>>>>>> to display it in local time needs the info.
>>>>>> This could just as well be a digital clock.
>>>>> 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.
>>>> That cannot be true.  It may work for your location, but I'm sure it
>>>> does not cover the general case under discussion.
>>> How can it not be true?  The time broadcast encodes both the time 
>>> (standard time) and whether or not DST is in effect.  Of course it 
>>> doesn't work for those jurisdictions that have chosen to go there own 
>>> way as far as DST is concerned.

"Standard time" (if you mean EST, PST...) doesn't make much
sense on a signal that covers many time zones.

I'm pretty sure WWVB transmits UTC.  You have to tell your clock
or watch the local time zone.  After that, it will do the 1 hour
offset in the spring/fall.  It will be a day or more late if
reception is poor on the magic night.

>> There you go.  It works for you, but it does not work in the general case.

>I think it works for most people and places.  Most of the US switches 
>to/from DST on the same day.  I don't know about the rest of the western 
>  hemisphere but since I seldom leave the continental U.S. it doesn't 
>really affect me very much.

"works for most people" seems like a silly claim.  What fraction of the
world's population live in the US?  (or within range of WWVB?)

These are my opinions, not necessarily my employer's.  I hate spam.

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