China time zone

Alois Treindl alois at
Thu Aug 18 15:15:35 UTC 2011

On 18.08.11 04:46, Paul Eggert wrote:
> Yes, the situation in China was quite different back then,
> but luckily for us our cutoff date is the POSIX epoch
> of 1970-01-01 00:00:00 UTC.  In the tz database we don't
> create a new zone merely because some locality had
> different clocks before 1970.  If we did, we'd need
> hundreds of zones for Indiana alone.

We (a group of timezone researchers for astrology purposes) are planning 
to do exactly that, create the required 300+ Indiana zones 
(Shanks/Pottenger uses 350+ but is not complete), to cover pre-1970 
Indiana timezone history.

It will take a lot of work and we understand that these extra zone will 
not get entry into standard tzdata file distribution. But I think if we 
maintain a separate 'history' zone fileset outside, tzcode will work 
with these extra zones of we include them in the zic compilation step.

For China as well.

Writing the zone files is only one part of the work, the other is 
describing precisely for which area the extra zones apply, and which 
area is covered by the existing standard tzdata zones.

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