[tz] [english 100%] Re: Irish Standard Time vs Irish Summer Time

Paul Eggert eggert at cs.ucla.edu
Fri Jan 19 21:04:52 UTC 2018

On 01/19/2018 12:31 PM, Yoshito Umaoka wrote:
> Java also imports time zone display name data from CLDR (BTW, CLDR uses
> "Irish Standard Time" as the long name). CLDR project cannot easily
> swap names for standard time and daylight saving time, because we also
> have many data consumers in various different implementations.

Thanks for your detailed summary. This "Irish Standard Time" usage has 
been a problem for many years, long predating tzdb-2018a. This is 
because "IST" stands for "Irish Summer Time" in Europe/Dublin timestamps 
before 1968-10-27, and for "Irish Standard Time" thereafter. This 
problem of mislabeling old timestamps is independent of the recent Irish 
tzdb changes, and if it were fixed I imagine that it wouldn't be that 
hard to support the approach taken by 2018a and 2018b. I can certainly 
see, though, why one might prefer to continue doing things the old way, 
even if it's not quite correct.

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