[Datetime-SIG] IANA TZ database statistics

Random832 random832 at fastmail.com
Thu Sep 24 03:12:59 CEST 2015

On Wed, Sep 23, 2015, at 20:47, Tim Peters wrote:
> [Alex]
> > I added a method to datetimetester [1] to compute some overall statistics on
> > tzfiles.  My code ignores "version 2" data, so I include only transitions
> > that fall within 32-bit time_t (1900 to 2038 range).
> From staring at zic.c, looks like (so far) the data in the version 2
> section is identical to that in the version 1 section, except written
> out in wider data formats.  The pretty clear intent is that they never
> intend to generate explicit transitions beyond 2037 in any version,

They do have transitions for before 1901, though.

> >  I think this is best we can do on Windows
> > where (IIRC) mktime does not work for times before epoch.  (What about
> > localtime?)

Windows has its own mechanism for storing timezone information, not
tzdata, but no, none of the MSVCRT functions work for times before 1970.

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