rok commented on code in PR #48002: URL: https://github.com/apache/arrow/pull/48002#discussion_r2478871611
########## docs/source/format/CanonicalExtensions.rst: ########## @@ -483,6 +483,28 @@ binary values look like. .. _variant_primitive_type_mapping: +Timestamp With Offset +============= +This type represents a timestamp column that stores potentially different timezone offsets per value. The timestamp is stored in UTC alongside the original timezone offset in minutes. + +* Extension name: ``arrow.timestamp_with_offset``. + +* The storage type of the extension is a ``Struct`` with 2 fields, in order: + + * ``timestamp``: a non-nullable ``Timestamp(time_unit, "UTC")``, where ``time_unit`` is any Arrow ``TimeUnit`` (s, ms, us or ns). + + * ``offset_minutes``: a non-nullable signed 16-bit integer (``Int16``) representing the offset in minutes from the UTC timezone. Negative offsets represent time zones west of UTC, while positive offsets represent east. Offsets range from -779 (-12:59) to +780 (+13:00). Review Comment: I believe (current) [timezones in the wild](https://en.wikipedia.org/wiki/List_of_UTC_offsets) cover a range of -12:00 to + 14:00. We could specify minute offsets should preferably be multiples of 15 minutes as [suggested here](https://en.wikipedia.org/wiki/UTC_offset): > By convention, every inhabited place in the world has a UTC offset that is a multiple of 15 minutes but the majority of offsets are stated in whole hours. There are many cases where the national [standard time](https://en.wikipedia.org/wiki/Standard_time) uses a UTC offset that is not defined solely by longitude. Alternatively - if we wanted to represent old sun time offsets - we'd have to consider [fractions of seconds](https://github.com/eggert/tz/blob/8e43ecbb256178b4fa7314491abdc0ce8f5f1c9c/northamerica#L329-L331). -- 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]
