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

Philip Paeps philip at trouble.is
Thu Jan 25 16:18:54 UTC 2018

On 2018-01-25 15:57:11 (+0000), Clive D.W. Feather wrote:
>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 happened.

At least Egypt and Morrocco have done this since 1990 (the arbitrary 
time before which CLDR considers irrelevant by policy).  Trivial to find 


Winter is hardly an appropriate description for these times of the year 
in those countries.  (In fact, the whole rationale for messing with time 
like this is because summer overlapping with Ramadan presents certain 


Philip Paeps
Senior Reality Engineer
Ministry of Information

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