Use hyphen-minus within ISO 8601 dates

[jesus2099]

I think it's maybe more convenient and less subject to conflict to keep hyphen-minus within ISO 8601 dates (YYYY-MM-DD) and stop replacing them with true hyphen.

https://community.metabrainz.org/t/correct-hyphen-unicode-hyphen-or-hyphen-minus/19610/68?u=jesus2099
https://tickets.metabrainz.org/browse/MBS-12152

[jesus2099]

At least it's worth discussing.

[kellnerd]

I am happy to change my script to leave dates alone (although that would be a bit annoying to implement with my current approach) if that is the outcome of a community discussion.
But I don't want to simply change this after 3 years of heavy usage and leave people confused (whether the script stopped working or if they should revert all their previous edits) without a clear consensus.

[jesus2099]

Yes, we sure have to wait! 😁👍

[raelthelamb]

(Sorry for the long comment.)

First some factual stuff:

The only relevant thing I can find in the Unicode Standard (Section 6.2, hyphens and dashes) is

When typesetting text, U+2010 hyphen is preferred over U+002D hyphen-minus.

which I guess we all know. I don't find anything more specific referring to dates.

ISO 8601 regarding date formats has in Section 3.4.1

The representations specified in this International Standard make use of graphic characters as specified in 3.4. Note that, except for “hyphen”, “minus” and “plus-minus”, these characters are part of the ISO/IEC 646 repertoire.
In an environment where use is made of a character repertoire based on ISO/IEC 646, “hyphen” and “minus” are both mapped onto “hyphen-minus”. Representations with a “plus-minus” shall only be used in such environment if the interchange repertoire includes “plus-minus”.

and

NOTE 2 Encoding of characters for the interchange of dates and times is not in the scope of this International Standard

(The link and the quotes refer to a draft, because the final version is, incredibly, paywalled.) The meaning of the paragraph in the first quote is disputed (e.g. here and here), in particular what it means for a character repertoire to be "based on ISO/IEC 646", and whether the large Unicode character set that MB uses is based on this or not. In the second quote, I am not sure if "interchange" includes display / typesetting.

And secondly an opinion:

When talking about display / typesetting (and not e.g. filenames), I can't really think of a reason to treat the hyphen in a date differently from other hyphens. So given that the decision to use U+2010 for hyphens in words seems fixed, I think it should be used in dates too.

(Were it completely up to me though, I would consistently use U+002D for all hyphens. Even the typesetting software TeX will actually replace U+2010 in input by U+002D in pdf output ... the Unicode standard itself looks like a TeX-produced document to me, which would explain why it always uses U+002D.)

Probably goes without saying, but if it is decided to use U+002D in dates, it would be lovely if the script could be updated to actually change the U+2010s back!

[jesus2099]

The only relevant thing I can find in the Unicode Standard (Section 6.2, hyphens and dashes) is

When typesetting text, U+2010 hyphen is preferred over U+002D hyphen-minus.
which I guess we all know. I don't find anything more specific referring to dates.

Yes but this is really just about language in general (they also talk about writing direction, CJK punctuation, etc.), not about dates.

I think we should at least align with MBS, that has always displayed dates with U+002D HYPHEN-MINUS, at the moment.