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Re: W3 Markup Validator - HTML5 <time> tag

From: Jukka K. Korpela <jkorpela@cs.tut.fi>
Date: Tue, 1 Mar 2016 16:17:23 +0200
To: testing Cakewalk Websites <testing8467@cakewalkwebsites.com>, www-validator@w3.org
Message-ID: <56D5A473.9050201@cs.tut.fi>
29.2.2016, 19:47, testing Cakewalk Websites wrote:

> When correctly adding structured data for opening hours according the
> schema.org <http://schema.org> and tested with the Google Structured
> Data Testing Tool
> <https://developers.google.com/structured-data/testing-tool/>: (enter
> this URL: http://www.oldtownvethospital.com)
> <p itemscope itemtype="http://schema.org/VeterinaryCare"><time
> itemprop="openingHours" datetime=
 > "Mo-Fr 08:30-17:30">Mon - Fri: 8:30 am - 5:30 pm</time></p>
> and shows up as “All good” in “VeterinaryCare (1)”.

It is still invalid HTML. The use of the datetime attribute of <time> in 
the schema, https://schema.org/openingHours , conflicts with the current 
HTML specs (and, as far as I know, any version of HTML that has the 
<time> element). It uses its own syntax for a date range, and a date 
range is not a thing that you can specify as a datetime attribute value. 
The values, as described at
https://html.spec.whatwg.org/multipage/semantics.html#attr-time-datetime
can only represent moments of time, a time range of a specific kind such 
as a day, a month, or a year, or a duration (amount of time) – not a 
range of time specified by its start and end. If the definition will 
ever be extended to allow such ranges, it is virtually certain that it 
will then use an ISO 8601 conformant notation, which is rather different 
from what Schema.org uses.

> The “Nu Html Checker” shows this as an error.

It’s just doing its job. It checks the document against applicable HTML 
(and some other) specifications.

> According to W3schools
> <http://www.w3schools.com/tags/att_time_datetime.asp>, the <time>
> attribute cannot contain day names (Monday - Sunday).

Let’s ignore w3schools since it is not in any way relevant in resolving 
this issue (and, in addition to being non-authoritative, it is unreliable).

>  1.
>     *Error*: Bad value |Mo-Fr 08:30-17:30| for attribute |datetime| on
>     element |time|
>     <http://www.w3.org/html/wg/drafts/html/master/single-page.html#the-time-element>:

Here the error message explains the problem with the value, and it links 
to the WHATWG HTML specification (using a link to a huge document 
containing the entire spec; above, I have mentioned a more handy 
address, pointing to a multipage version of the spec).

>     The literal did not satisfy the time-datetime format.
>      From line 222, column 79; to line 222, column 137
>     |naryCare"><time itemprop="openingHours" datetime="Mo-Fr
>     08:30-17:30">Mon - |

This means that "Mo-Fr 08:30-17:30" is not valid, since it does not 
match any of the allowed patterns for the attribute value. This is a 
purely syntactic statement, and the validator’s job ends here.

But the point is that a date range *cannot* be represented as a datetime 
value at all. In practice, it is not a matter of making a mistake when 
trying to write a range in the correct syntax; there simply is no 
correct syntax for it in this context.

Consequently, using the <time> element at all is wrong, as a matter of 
HTML rules. I suggest that you raise the issue in some suitable forum 
related to Schema.org development. If you ask me, they should simply use 
some other element and attribute names, even though it means that in 
“pure” HTML (as opposite to HTML extended with custom elements), you 
would need to use <span>.

Yucca
Received on Tuesday, 1 March 2016 14:17:08 UTC

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