pitrou commented on PR #47316: URL: https://github.com/apache/arrow/pull/47316#issuecomment-3209795917
So let's go back to the two specifications. ### The Parquet spec From the [logical types specification](https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#local-semantics-timestamps-not-normalized-to-utc): > A TIMESTAMP with isAdjustedToUTC=false represents year, month, day, hour, minute, second and subsecond fields in a local timezone, regardless of what specific time zone is considered local. ### The Arrow spec From the [Flatbuffers definition](https://github.com/apache/arrow/blob/0ecc472c7858471f17d52fd542eef9cc20390b4d/format/Schema.fbs#L258-L260): > Time is either a 32-bit or 64-bit signed integer type representing and elapsed time since midnight, stored in either of four units: seconds, milliseconds, microseconds or nanoseconds. ### Discussion The Arrow spec deliberately does not disambiguate the point of reference for the Time type. It's simply "midnight". It's not expressed in any particular timezone. Based on this, I would conclude that not only writing the Arrow Time type with `isAdjustedToUTC=false` is ok, **it should even be the default**. -- 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: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
