[whatwg] Historic dates in HTML5

[Bruce Lawson]

Here are some (randomly selected) examples of microformats that are  
already being used to mark up historical dates in wikipedia, of the kind  
that would be illegal for 2 reasons; firstly, because they are not in the  
future, and also because they aren't precise (eg full YYYY-MM-DD format)  
or are ancient.

http://en.wikipedia.org/wiki/Public_Worship_Regulation_Act_1874
http://en.wikipedia.org/wiki/Septennial_Act_1715
http://en.wikipedia.org/wiki/George_Washington_Carver
http://en.wikipedia.org/wiki/John_Everett_Millais (birth date in hCard)
1066 has one hCalendar, with: <SPAN class="summary dtstart">1066</SPAN> :  
http://en.wikipedia.org/wiki/1066

In my opinion, in order for the time element to succeed, it must be  
capable of doing the same job as microformats, or - as Henri says - the  
time element will not succed.

Andy Mabbett has already listed use cases
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-February/018639.html

"Use-cases for machine-readable date mark-up are many: as well as the
aforesaid calendar interactions, they can be used for sorting; for
searching ("find me all the pages about events in 1923" — recent
developments in Yahoo's YQL searching API (which now supports searching
for microformats):

   <http://developer.yahoo.net/blog/archives/2009/01/yql_with_microformats.html>

have opened up a whole new set of possibilities, which is only just
beginning to be explored). They can be mapped visually on a "SIMILE"

   <http://simile.mit.edu/timeline/>

or similar time-line.  They can be translated into other languages more
effectively than raw prose; they can be disambiguated (does “5/6/09"
mean “5th June 2009? or “6th May 2009"?); and they can be presented
in the user's preferred format."

I suggest that the short list of apps that consume microformatted  
historical data should not be used to indicate that it's not a worthwhile  
use case. After all, I know of no user agents that can use time, section,  
footer, datagrid etc but we mostly expect there to be soon.


-- 
Bruce Lawson
Web Evangelist
www.opera.com (work)
www.brucelawson.co.uk (personal)