I compared the list of ICU-recognized time zone names with the names
in CLDR's supplementalData.xml. Some of the differences are perfectly
fine. For example, ICU adds legacy names like ACT, AET and such.
However, there are other differences that I propose to eliminate by
a) CLDR has SystemV/XXX names but ICU does not. (tzdata file systemv)
CLDR has them for stabilization - tzdata used to have them, but recent
systemv files have these zones commented out. In CLDR, they are
aliases, like SystemV/YST9YDT->America/Anchorage.
I propose to add the SystemV/XXX names to ICU.
b) ICU has Asia/Riyadh87 and similar (3 zones with aliases) but CLDR
does not. (tzdata files solar87..solar89)
These represent an abandoned experiment. In these zones, each day of
1987-1989 has its own rule, adjusting official time to astronomical
time. Therefore, they have 365/366 transitions times each in ICU's
I propose to remove the Riyadh<yy> names from ICU.
c) CLDR is adding the Etc/Unknown name, similar to ZZ for region
codes. ICU currently does not support this name (naturally).
I propose to add Etc/Unknown to ICU. As a TimeZone object, I will make
it work exactly like GMT, but I won't make it a real alias to GMT so
that they are different.
d) ICU has "Factory" but CLDR does not.
>From the tzdata factory file:
# For companies who don't want to put time zone specification in
# their installation procedures. When users run date, they'll get the message.
Maybe we could have used this one instead of inventing Etc/Unknown,
but I think it's not a perfect fit, it's a little late for that, and
CLDR has excluded this for a long time.
I propose to remove "Factory" from ICU.
The remaining differences would just be the legacy names added to ICU:
ACT, AET, AGT, ART, AST, BET, BST, CAT, CET, CNT, CST, CTT, EAT, ECT,
EET, IET, IST, JS6, MET, MIT, NET, NST, PLT, PNT, PRT, PST, SST, VST,
Please reply by next Wednesday, 2006-nov-01.
Opinions expressed here may not reflect my company's positions unless