[tz] Belarus is listed in MSK timezone

[Paul Eggert]

Dzmitry Kazimirchyk wrote:
> I would agree with one rule set - one name policy if it was strictly observed by
> the TZ database.

That would require inventing names for time zones, and we try to avoid doing 
that when possible.  The goal is to describe timekeeping practice, not to 
prescribe it.  In hindsight the tz database could have supported having no 
abbreviation for zones where abbreviations are not commonly used, and this would 
have avoided some similar problems elsewhere where we use "zzz" for time zone 
abbreviations in some cases; but this would have entailed some confusion and/or 
compatibility hassles at the time the database was being introduced and it's 
impractical to revisit this design decision now.

The situation with MSK is not unprecedented.  For example, in the tz database 
PST stands for "Pacific Standard Time" in the United States, and for "Pitcairn 
Standard Time" in Pitcairn, and corresponds to UTC-8 in both countries.  This is 
entirely analogous to MSK standing for "Moscow time" in Russia and for "Minsk 
time" in Belarus and corresponding to UTC+3 in both countries.  For timekeeping 
purposes it's often a bit simpler to use the same abbreviation for the same UTC 
offset even if the abbreviation is ambiguous, and this hasn't been a significant 
technical problem in practice.