Metazone timestamps

Yoshito Umaoka via CLDR-Users cldr-users at
Wed Nov 1 10:30:48 CDT 2017

> In
> there is an example:
> <timezone type="America/Indiana/Knox">
>   <usesMetazone to="1991-10-27 07:00" mzone="America_Central"/>
>   <usesMetazone to="2006-04-02 07:00" from="1991-10-27 07:00" 
> mzone="America_Eastern"/>
>   <usesMetazone from="2006-04-02 07:00" mzone="America_Central"/>
> </timezone>
> It also states: “Note that the dates and times are specified in UTC,
> not local time.”


> As currently presented, they appear to be local time.  Is there a 
> reason these aren't just expressed as ISO 8601 timestamps with a 
> trailing Z?  In other words:  “1991-10-27T07:00Z”
> Note that ISO 8601 allows for a space instead of a T, so these 
> timestamps are ISO 8601 compliant, but also that in absence of a Z 
> or an offset they are required to be interpreted as local time. 

I guess the original author/designer of this data did not really care 
about ISO 8601 conformance.

> I’ve certainly made this mistake in interpreting them before.  I’m 
> sure others have as well.  Would it be possible to change this in a 
> future version?

I actually felt the same when I started maintaining the data.
Personally, I'm fine to change the date/time string to be ISO UTC time 
format (and use the default date/time separator - 'T'), then update the 
spec to explain it's ISO 8601 UTC date/time format explicitly.

But, this change may break existing code utilizing this data, so we 
probably need to discuss this in CLDR TC.

Anyway, can you file a CLDR ticket?

> Thanks,
> Matt Johnson
> Microsoft

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