<i18n dev> TZ database 2021b changes

Naoto Sato naoto.sato at oracle.com
Thu Sep 30 17:33:52 UTC 2021

Hi Yoshito,

We at Oracle had discussed this, but still have not yet decided the 
direction. We have an issue to upgrade the JDK for 2021b:


I will update the issue as things are decided.


On 9/28/21 8:34 AM, Yoshito Umaoka wrote:
> Hello OpenJDK i18n dev team,
> As you may already know, TZ database 2021b was released last week, and 
> it contains some drastic changes for pre-1970 rules. Multiple zones 
> sharing post 1970 rules were merged into one, and they were moved to 
> backward file. Pre-1970 rules used for these merged zones in 2021a were 
> in backzone file, but it's not a part of standard package.
> In the tz mailing list, many TZ database consumers are worrying about 
> this move. It looks not a small number of people are against this 
> change, and some are considering to maintain database separately to 
> maintain rules for pre-1970 dates.
> I'm curious about what Java i18n team will do for this. Do you plan to 
> accept the changes done in TZ database 2021b as-is? Or do you plan to 
> preserve rules in backzone?
> We discussed this topic in Unicode ICU team meeting last week. We don't 
> have long term strategy yet. However, DST change in Samoa is already in 
> effect, we're going to ship a quick patch including 2021b zone rule 
> updates applied on top of 2021a for now (today or tomorrow).
> -Yoshito

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