[GLib] Allow to create time and timestamp arrays with a time zone

[esodan]

Describe the enhancement requested

Current API to create a GArrowTimestamp, requires a GArrowTimestampDataType.

An GArrowTimestampDataType can be created but only is possible to define its time units; there isn't an API to create one adding a time zone as in PyArrow.

So a new garrow_timestamp_data_type_new_with_timezone() method is required using the following signature:

GArrowTimestampDataType *
garrow_timestamp_data_type_new_with_timezone (GArrowTimeUnit unit, GTimeZone* tz);

This should help GLib users to create timestamps with a time zone.

Above will require to add a method to get the current GTimeZone:

GTimeZone *
garrow_timestamp_get_timezone (GArrowTimestampArray *array);

Above API should be the added too, to GArrowTime32Array and GArrowTime64Array arrays, so is easy to know the time zone the time is representing.

Component(s)

GLib

[kou]

Timezone support for GArrowTimestampDataType makes sense but it's for GArrowTime{32,64}DataType doesn't make sense. Because GArrowTime{32,64}DataType is seconds/milliseoncs/microseconds/nanoseconds since midnight: https://arrow.apache.org/docs/cpp/api/datatype.html#_CPPv4N5arrow10Time32TypeE

[esodan]

Timezone support for GArrowTimestampDataType makes sense but it's for GArrowTime{32,64}DataType doesn't make sense. Because GArrowTime{32,64}DataType is seconds/milliseoncs/microseconds/nanoseconds since midnight: https://arrow.apache.org/docs/cpp/api/datatype.html#_CPPv4N5arrow10Time32TypeE

I see. While I'm not an expert on time issues, but Time Zone could affect Date{32|64}; is it?

[kou]

Time zone doesn't affect Date{32,64}. Because they are the number of days since UNIX epoch: https://arrow.apache.org/docs/cpp/api/datatype.html#_CPPv4N5arrow10Date32TypeE

Time zone doesn't change the number of days.