KEP #2: datetime RFC3339 and ISO 8601 and requirement of tz

Bernhard Reiter bernhard at
Thu Mar 3 09:42:11 CET 2011

Am Dienstag, 1. März 2011 18:44:34 schrieb Till Adam:
> > BTW:
> >
> > does not say anything about RFC3339 for instance, only about ISODate.
> > This probably is why the QMailTimeStamp implementation from Qt
> > labs/messagingframe work uses
> > else if (format == QMailTimeStamp::Rfc3339) {
> >        result = QString( originalTime.toString( "yyyy-MM-ddThh:mm:ss%1" )
> > ); result = result.arg( utcOffset == 0 ? QString("Z") :
> > QString().sprintf( "%+.2d:%.2d", hOffset, mOffset ) );
> > (They claim they cannot use QDateTime for localisation reasons.)
> They are not using QDateTime's localized day and month names, that's
> unrelated to this discussion. And they are writing out the offset you find
> so confusing, which implementors of KEP2 could, but do not have to do.

Implementors of KEP2 id=10864 MUST write the offset out when UTC is
not authoritative. And Qt does not seem to have a simple RFC3339 write 

KEP2: "All datetime fields MUST be formatted according to RFC 3339"
RFC3339: "time-offset     = "Z" / time-numoffset"

My suggested alternative would be close to RFC3339 and replace
their rules with something like

time-secfrac    = "." 3DIGIT
time-offset     = ["Z"] ; without Z, there is an accompaining tz attribute

And fixed upper case "T" and "Z" where they appear.

This seems sensible as we force the tz tag when UTC is not authoritative.
RFC3339 say not to deal with timezones, this is why they have added the 
time-numoffset. We deal with timezones, so it makes sense to use a difference

My above suggestion seems to be another subset of ISO 8601 (according to the 
Appendix A ISO 8601 Collected ABNF from RFC3339). 

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