[tz] Large scale changes proposed in 2014f

Stephen Colebourne scolebourne at joda.org
Fri Aug 1 12:10:08 UTC 2014

On 1 August 2014 01:20, Paul Eggert <eggert at cs.ucla.edu> wrote:
> Stephen Colebourne wrote:
>> The differences between 2014e and 2014f-proposed can be seen here:
>> https://github.com/jodastephen/tzdiff/commit/c812da9e12bd6f8aa52fa2dd758e236581c23a29
> I don't normally use a web-based interface, though; I use 'git' directly.
> For example, on my development host the shell command 'git diff 2014e'
> outputs a text file containing all the changes since 2014e.

The key reason for generating the tzdiff link is to be able to check
what the *end result* of the changes is. ie. sometimes it is a lot
easier to see the actual result of the changes when resolved into
actual transitions.

>> - Africa/Accra gains DST between 1920 and 1935

Based on your explanation, this looks like a good change with a good
justification. Can any more detail be added to NEWS?

>> - Africa/Freetown loses its entire history of DST

Thank you for the explanation. This level of detail helps. However
while this indicates that the current data is wrong, your explanation
does not indicate that replacement is right. This is the nub of the
problem. (Determining "right" is of cause hard if even possible for
these locations). In this case your explanation goes just about far
enough to say that removal is justified, but the single Linked 1912 is
not explained.

The same applies to the other conversion to links. In each case, the
LMT changes and often the year that standard time starts is changed.
I, and others, would strongly prefer the data to be left alone until
research shows something clearly better. If filtering to reduce the
size of the database is needed, then it should be done in code, not
the in original source data.


More information about the tz mailing list