[tz] North Korea into +8:30 time zone

[Howard Hinnant]

On Aug 7, 2015, at 8:28 PM, Paul Eggert <eggert at cs.ucla.edu> wrote:
> 
> tzdata entries for circa 1954-1961 timestamps do use "KST" to abbreviate time in Korea regardless of whether it was North (+0900) or South (+0830) Korea. However, this was purely my invention, as far as I know it has no basis and we should probably fix this too at some point.  We used to be pretty loose about this sort of thing but we should steer the tz database in the direction of recording what's known instead of making stuff up.

As a purely symbolic gesture of support for this direction, I’ve implemented %z in my C++14 tz parser:

https://github.com/HowardHinnant/date/commit/28eadffa06aa381d5ca7e2bb8893a61e2c7e07e7

Howard