[tz] Why did you rename Russian zone name abbreviations

Alexander Belopolsky alexander.belopolsky at gmail.com
Thu Nov 3 17:26:40 UTC 2016


On Thu, Nov 3, 2016 at 11:47 AM, Paul Eggert <eggert at cs.ucla.edu> wrote:

> On 11/03/2016 08:27 AM, Alexander Belopolsky wrote:
>
>> Isn't this problem worse with the UTC offset?
>>
>
> Only if one assumes that a time zone abbreviation reflects the user's
> location, so that VLAT means "Vladivostok time, whatever that happens to
> be". In English the usual assumption is that a time zone abbreviation
> reflects the user's UTC offset, so that CST means "US Central Standard
> Time, 6 hours behind UTC", even if one's location is Mérida (which is not
> in the central US or even in central North America). A numeric abbreviation
> matches this usual assumption better than VLAT does.


Yes, I've been inconvenienced by the fact that MSK does not always mean +03
(or was it +04 or +02 back then?), but does the convenience of having an
unambiguous  many to one mapping of abbreviations to UTC offsets outweigh
the problem of date command output from older systems being no longer
parseable?

I think the disruption could be minimized by postulating the current values
and only changing the historical data where the postulated values are not
correct.  For VLAT it means postulating that VLAT=UTC+10 and changing VLAT
to +11 for times prior to the last reform of 2014.

In the good old times Russia (USSR) had a way to deal with varying UTC
offsets.  We had the notion of the "decree time".  When Moscow transitioned
from UTC+02 to UTC+03 in the early XX century, the new timezone was still
called the 2nd timezone, but the new time was distinguished as Moscow
Decree Time (and if anyone would come up with an abbreviation back then -
it would probably be MDT or in the contemporary style MosDeTi :-).
Unfortunately with a later introduction of the Summer Time (and briefly
Double Summer Time) the term Decree Time became ambiguous.  I remember that
when Decree time was reintroduced in the 90s together with the Summer time,
some people incorrectly referred to the Summer time as Decree time and for
this reason the term Decree time was disfavored.

In any case, while I agree that in theory the new scheme is somewhat better
than the old one, changes like this that are not driven by the actual
change in timekeeping practices should not be made without soliciting input
from users in the affected regions first.
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