[mapserver-dev] "ambiguity" of gml_[item name]_type = Date

[Even Rouault]

Hi,

when serving vector through WFS currently, we can use the gml_[item name]_type 
to define the type of a field. Currently we have a value "Date" whose 
semantics is rather loose. All input backends (OGR, Oracle, MSSQL, PostGIS) 
use it whereas they have distinct types for Date (without time), DateTime, and 
Time (without date). MapServer having internally a single type makes that when 
using OGR output (for example GeoJSON), we'll have lost some information, and 
thus the OGR output currently prefers to use a OGR OFTDateTime to avoid 
potentially losses. But "2019-10-22T00:00:00Z" is not semantically equivalent 
to "2019-10-22".
So my proposal would be to change (define) Date to be a Date without time 
information, and add DateTime and Time types.

Thoughts ?

(note: some backends like Oracle and PostGIS have distinctions between 
DateTime with or without timezone, but we probably don't need to go to that 
level of subtelty)

Even

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