MaxGekk opened a new pull request #28816: URL: https://github.com/apache/spark/pull/28816
### What changes were proposed in this pull request? TODO Note: The fix assumes that transitions cannot happen more often than once per 2 days. ### Why are the changes needed? Current implementation handles timestamps overlapping only during daylight saving time but overlapping can happen also during transition from one standard time zone to another one. For example in the case of `Asia/Hong_Kong`, the time zone switched from `Japan Standard Time` (UTC+9) to `Hong Kong Time` (UTC+8) on _Sunday, 18 November, 1945 01:59:59 AM_. The changes allow to handle the special case as well. ### Does this PR introduce _any_ user-facing change? It might affect micros rebasing in before common era when not-optimised version of `rebaseJulianToGregorianMicros()` is used directly. ### How was this patch tested? 1. By existing tests in `DateTimeUtilsSuite`, `RebaseDateTimeSuite`, `DateFunctionsSuite`, `DateExpressionsSuite` and `TimestampFormatterSuite`. 2. Added new checks to `RebaseDateTimeSuite`.`SPARK-31959: JST -> HKT at Asia/Hong_Kong in 1945`. 3. Regenerated `julian-gregorian-rebase-micros.json` with the step of 30 minutes, and got the same JSON file. The JSON file isn't affected because previously it was generated with the step of 1 week. And the spike in diffs/switch points during 1 hour of timestamp overlapping wasn't detected. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
