andygrove commented on issue #9183: URL: https://github.com/apache/arrow-rs/issues/9183#issuecomment-6088125597
Adding a concrete downstream motivation for the timezone part of this. apache/datafusion-comet#6816 tracks native results diverging from Spark after 2099: chrono-tz stops applying daylight saving after its last precomputed transition, while `java.time` keeps applying the zone's last rules. That is the same horizon @mzabaluev describes above, and it shows up in Spark as `date_trunc`, `hour`, and timestamp casts being off by an hour for summer dates in DST zones. To get something concrete to discuss, I opened #11482 as a draft. It adds an opt-in `jiff` feature that swaps only the engine behind `arrow_array::timezone::Tz`, keeping the chrono `TimeZone` trait impl, `Copy`, display, and error text unchanged, so downstream code does not change. The existing `chrono-tz` integration tests pass against it. The open questions (bundled versus system tzdb, the interning needed to keep `Tz: Copy`, and years beyond 9999) are listed in the PR description. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
