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

John Hasler john at dhh.gt.org
Fri Jun 19 20:35:47 UTC 2009

Rob writes:
> The offset from UTC is not the kind of timezone information that is being
> discussed here.

Sure it is.

>  It cannot be distributed via NTP anyway, as the server does not know
> where the client is and thus cannot give it the offset info.


> The interesting information is the DST schedule in use at the different
> areas.

That is part of the timezone data.

> The client will have to know in which area it is and then can request the
> timezone information for that area, which tells it what the offset is at
> that specific moment.

The client may very well need information on zones other than the one it is
located in.  It should check the nearest tzdata server for a standard
tzdata file newer than the one it has and fetch it via a standard protocol
from a well-known location on the nearest of a set of well-known servers.
If it's an embedded system with minimal storage it can throw a way the
stuff it doesn't need.

We have a standard file.  Ftp will do fine as a protocol.  We just need to
agree on a standard location for the current tzdata file and its timestamp
and recruit a distributed set of servers.  The NTP pool servers would do
nicely.  The client to periodically check for new tzdata files would be
John Hasler 
john at dhh.gt.org
Dancing Horse Hill
Elmwood, WI USA

More information about the questions mailing list