IANA Time Zone Database has been upgraded to 2024b in the JDK. This version mainly includes changes to improve historical data for Mexico, Mongolia, and Portugal. It also changes one timestamp abbreviation, for the time zone 'MET'. Also Asia/Choibalsan is now an alias for Asia/Ulaanbaatar.

The new tzdata changes also impact some legacy time zone IDs. As per 2024b changes "EST"  links to "America/Panama", "HST" links to "Pacific/Honolulu" and "MST" links to "America/Phoenix". To preserve Java SE specification, the `java.time.ZoneId.SHORT_IDS` Map has not changed in JDK. Further details are available at https://bugs.openjdk.org/browse/JDK-8342331