[Tagging] date not in YYYY-MM.DD format should go into a sufix edtf ?

[Minh Nguyen]

Vào lúc 14:56 2023-05-29, Marc_marc đã viết:
> a contributor change to wiki to tell that "For dates that cannot be 
> expressed in YYYY-MM-DD format, such as approximate or uncertain dates, 
> or times of day, use the end_date:edtf=* key in addition to this key. "
> 
> did you agree with that ?
> start_date if full of not YYYY-MM-DD including Cxx for historical monument

This was in the section titled "OpenHistoricalMap", so the intention was 
not to provide guidance on tagging in OSM. OHM has long preferred EDTF 
over the "questionable, contentious or controversial" ad-hoc scheme that 
the start_date=* page has described for OSM. I added this passage about 
EDTF because sometimes OHM mappers get confused, entering the ad-hoc 
format in start_date=* and end_date=* and expecting it to do something. [1]

After making that change, I realized it was really confusing to have 
both OSM and OHM guidance about start_date=* or end_date=* on a single 
page, because the two projects have fundamentally different approaches 
to dealing with historical data (and for good reason). I split out a 
separate page for the OHM guidance so that the OSM guidance can be 
clearer to OSM mappers. Fortunately, these differences are confined to 
only a few keys. Otherwise, OHM has been following OSM's tagging 
conventions to a tee.

Having tried to use both formats in both projects, I do think EDTF is 
the better format overall, and I wouldn't mind seeing it used in OSM. 
However, the ad-hoc format does have one advantage in being able to 
express dates in the Julian calendar directly, rather than making 
mappers perform the conversion themselves.

[1] https://github.com/OpenHistoricalMap/issues/issues/547

-- 
minh at nguyen.cincinnati.oh.us