Subject: Re: Bug#407476: coreutils: Another comment regarding ISO 8601

From: Michael Stone <[email-masked]>
Date: Tue, 17 Mar 2015 07:25:49 -0400

I generally am very receptive to arguments based on standards 
compliance, but in this case, no way.

On Mon, Mar 16, 2015 at 10:43:28PM -0700, you wrote:
>ISO 8601 also requires that date offsets less than UTC (e.g. "−5:00") use a "−" ("minus sign" U+2212); not a "-" ("hyphen-minus" U+002D) as is printed.

AFAICT ISO 8601 specifies "hyphen". I don't see that there is any 
reference to unicode in the standard. Full disclosure: I'm not working 
from an official document of record since ISO charges for their 
standards.

I would be somewhat shocked to find a parser that accepted U+2212, and 
flabbergasted to find one that did not accept U+002D.

I would be surprised if the standard did mandate a character that would 
preclude the standard from being used in many contexts where it works 
well today in plain ASCII. 

If someone can actually show that ISO 8601 requires the hyphen to be a 
non-ascii unicode character my course would likely be to simply document 
non-compliance. Changing the character would break working systems.

Mike Stone