tzdata 2003e: imperfections

Olson, Arthur David (NIH/NCI) olsona at
Mon May 17 14:28:23 UTC 2004

>             9:00    ROK    K%sT
> ...
> Since South Korea no longer observes DST, it would be better for the
consistency of the database if the last line was changed into:
>             9:00    ROK    K%sT 1988 Oct
> and an extra line was added, like:
>             9:00    -    KST

Generally speaking, we want to have the last line of a Zone refer to a Rule
line. This is particularly important in cases where a country has multiple
time zones.
If the country decides in the future to change the way DST is handled (for
example, decides to start observing DST again), we can make things right by
changing one Rule rather than by changing multiple Zones.

> The software will give the correct time for e.g. this moment I guess,
because no Rule line can be found, valid for May 2004.
> So, changing the database files for this could get a low priority, but it
is still an imperfection!

Remember that the Rules tell when DST transitions happen; in the above case,
the Rule that's valid is one that specifies the last transition before May
2004, which is assumed to be in effect in perpetuity.


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