[tz] OpenJDK/CLDR/ICU/Joda issues with Ireland change

Clive D.W. Feather clive at davros.org
Thu Jan 25 15:57:11 UTC 2018

Yoshito Umaoka said:
> CLDR does not determine offsets. CLDR just maintains an array of names
> by category. In CLDR, we define several different type of names for
> a zone (and localized names in various locales) -
> 1. Long standard (e.g. Pacific Standard Time)
> 2. Long daylight (e.g. Pacific Daylight Time)
> 3. Long generic (e.g. Pacific Time)
> 4. Short standard (e.g. PST)
> 5. Short daylight (e.g. PDT)
> 6. Short generic (e.g. PT)

What about the name for the third offset each year? The UK used to use
three offsets during the year. I'm sure it was not alone. I'm certainly not
sure that it won't happen again.

What if the same offset has different names in different contexts? A
majority-Muslim country that puts its clocks back for Ramadan (I believe
such exist) might use the names XXX Winter Time, XXX Summer Time, and XXX
Ramadan Time, the last to make it clear that it's not because of winter.

If your answer is "we'll deal with that when it happens" then, well, it's

> And the set of name may change time to time for a single location.

But then you say:

> CLDR sets an assumption that name of zones are very stable. For example,
> "Pacific Standard Time" represents standard time used on US Pacific coast
> and the name itself does not change time to time.

Within my lifetime "BST" has been both Short Daylight and Short Standard
(in your terminology) for my timezone.

Clive D.W. Feather          | If you lie to the compiler,
Email: clive at davros.org     | it will get its revenge.
Web: http://www.davros.org  |   - Henry Spencer
Mobile: +44 7973 377646

More information about the tz mailing list