Thanks for the helpful comments! On Tue, 28 Jan 1997, Markus G. Kuhn wrote:
1) Format
If it is really necessary to include a registered time zone algorithm identifier, then I would prefer to see it appended to the ISO 8601 string as in
1999-12-31T23:59:59-05:00/America/New_York
If you allow to insert a fields between the time and offset (which is not supported by ISO 8601) and insert spaces into the format, then this is a serious deviation from ISO 8601 and you could also allow the replacement of the "T" by a space as well ...
I do believe we need a new format for future times where the timezone name is authoratative, it could potentially be split into a separate document if that was thought to be helpful. The primary need for this is to specify future and recurring events for the calendaring and scheduling work. The zone offset hint in the local format has very different semantics from the zone offset in ISO 8601, so I felt it was important to use a different syntax for it. The basic idea was to take the ISO 8601 local time format, append the timezone name to fully qualify it, then the optional offset hint. As far as I'm concerned, any reasonable syntax for the stuff after the ISO 8601 local time is fair game.
2) Logic errors in above example
Thanks. I'll fix those in the next draft.
3) Rounding of timestamps:
Good idea. I'll add it in the next draft.
4) Time zone registry
What I wanted to avoid was having the IETF/IANA take over the work currently being done by the timezone mailing list to maintain the timezone archives. What I wanted to do was to give a "standards blessing" to the names used in the timezone archive, without pretending that the IANA (or anyone on the Internet) can keep a set of zone rules which have standards-level authority.
The suggested template for a time zone registration request should contain a formal notation for the time zone algorithm. Candidates are the zic and the POSIX TZ formats, with the former one being much more flexible.
The POSIX format is obviously inadequate. But I really don't want IANA to register the zone rules -- I just want a registry of the zone names. The zone rules can be found two ways: through informal channels on the Internet, or by contacting the appropriate government. Frankly, I think this list is doing a superb job of maintaining zone rule archives and have no interest in competing with it or mucking with the current functional process.
The nature of the name space (time zone identified by the English name of the largest populated ares in this zone, etc.) should be specified and a rationale should be given for it (see the tz africa file for Paul's background information about the namespace design).
Good idea. I didn't notice that before. I will suggest one change to Paul's rules -- namely that "-" be used to represent spaces in future names rather than "_". It turns out that "_" causes problems in a number of contexts (some non-english countries, underlined words, terminal screen with blinking underscore cursor, some printing contexts).
The description of the role and purpose of the IANA time zone registry is a little bit unclear.
Yeah. I'll work on it.
the case, then in addition to the ISO country code, the registry should contain a reference coordinate that identifies the registered location.
That does make sense. Agreed.
During the switch from summer time back to winter time, usually one hour occurs twice. Your local format (as now the location identifier and not the offset is authoritative) distinguishes not any more uniquely between these two hours.
True. Summer time is really a pain. Your suggestion is quite reasonable -- I'll add it to the next draft.