Bug ID: JDK-8317979 Use TZ database style abbreviations in the CLDR locale provider

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JDK 22
22 b21Fixed

CLDR provides very few short names for time zones, such as PST/PDT. This will typically end up substituting names from the COMPAT provider. Once the COMPAT is removed, they will be displayed in the GMT format, i.e., GMT+XX:YY. Although the short names in the COMPAT provider are somewhat questionable (some less common ones are simply made up from the long names by taking the initials), it would be not desirable for them to fall back to GMT format.
To mitigate the situation, CLDR can use the abbreviated names from the TZ database, which contains legacy (major) short names as FORMAT. The CLDR provider can use them instead of the GMT offset style. This enhancement is a precursor to the future removal of the COMPAT provider.

Changeset: ce8ebebc Author: Naoto Sato <naoto@openjdk.org> Date: 2023-10-18 18:26:49 +0000 URL: https://git.openjdk.org/jdk/commit/ce8ebebc77f4ef73852364f6188b43c482337350
18-10-2023
And here is my reply to the comment in the pr (https://github.com/openjdk/jdk/pull/16206#issuecomment-1767274871): ``` > This is intentional, because these short names may not be known to users. Do you have data that ja-JP, zh-CN, de-DE users expect and are familiar with `PST/PDT`? This is why CLDR fallback rules would fall back to `Los Angeles Time` for example in the longer name. It's not short, but it's understandable, and the numeric offset can work for short. Yes, I am saying not having short names is not a bad thing, or rather better than making up uncommon names among those locals (which COMPAT is doing). GMT offset style is totally acceptable in such cases IMO. In fact, TZ database is getting away from using old three-letter short names. > I'd encourage engaging with CLDR-TC to discuss the short names upstream if you have data on the recognizability of these short names. In fact, CLDR probably has _too many_ short names for zones. No, I don't have any data on this. At least I can say that there are no short names for those in Japanese. ```
17-10-2023
Just voicing my comment here cc'ed from the pull request: This (few short names) is intentional, because these short names may not be known to users. Do you have data that ja-JP, zh-CN, de-DE users expect and are familiar with PST/PDT? This is why CLDR fallback rules would fall back to "Los Angeles Time" for example in the longer name. It's not short, but it's understandable, and the numeric offset can work if a shorter name is needed. I'd encourage engaging with CLDR-TC to discuss the short names upstream if you have data on the recognizability of these short names. In fact, CLDR probably has too many short names for zones.
17-10-2023
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/16206 Date: 2023-10-16 19:57:12 +0000
16-10-2023

Blocks :	JDK-8174269 - Consider removing COMPAT provider from JDK
Relates :	JDK-8322647 - Short name for the `Europe/Lisbon` time zone is incorrect