[tz] Letter/s for half hour daylight saving

[Tobias Conradi]

I just discovered that there is some precedence to use different
lettering for half hour saving time.

ftp://ftp.iana.org/tz/data/australasia
Rule Cook 1978 only - Nov 12 0:00 0:30 HS
Rule Cook 1979 1991 - Mar Sun>=1 0:00 0 -
Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 HS
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua
-10:30 - CKT 1978 Nov 12 # Cook Is Time
-10:00 Cook CK%sT

So the recent LHHT did only deviate insofar as to use one letter (H)
instead of two (HS).

I added HS to the IANA time zone database documentation of
abbreviations hosted at anna.info :

http://anna.info/x/wiki/w/index.php?title=IANA_time_zone_database&diff=82&oldid=79

--
Tobias Conradi
Rheinsberger Str. 18
10115 Berlin
Germany

http://tobiasconradi.com/