Re: [whatwg] <time>

Hi David,

On 10 Mar 2009, at 17:03, David Singer wrote:

>
> The trouble is, that opens a large can of worms.  Once we step out  
> of the Gregorian calendar, we'll get questions about various other  
> calendar systems (e.g. Roman ab urbe condita <http:// 
> en.wikipedia.org/wiki/Ab_urbe_condita>, Byzantine Indiction cycles  
> <http://en.wikipedia.org/wiki/Indiction>, and any number of other  
> calendar systems from history and in current use).  Then, of  
> course, are the systems with a different 'year' (e.g. lunar rather  
> than solar).  And if we were to introduce a 'calendar system  
> designator', we'd have to talk about how one converted/normalized.
>

This is already a solved problem in the Text Encoding Intiative  
(TEI). The value of a date/time is encoded in the Gregorian calendar,  
using ISO8601. The calendar attribute is used to indicate the  
calendar of the original, written date enclosed in the tags.
eg. from the TEI docs for dates and times
<date calendar="Julian" value="1732-02-22">Feb. 11, 1731.</date>
I suggested that the calendar attribute be adopted in HTML5, as it  
would be useful to those of us who mark up historical texts in HTML.  
We can't change the author's original written dates, but it would be  
useful to normalise documents using the Julian calendar to proleptic  
Gregorian dates.

See http://www.tei-c.org/Guidelines/P4/html/ref-DATE.html and the  
associated guidelines on publishing dates and times
http://www.tei-c.org/Guidelines/P4/html/CO.html#CONADA

>
> Adding a range construct to 8601, or having a range construct  
> ourselves using 2 8601 dates, seems like something we could ask for  
> or do.
>
>
8601 already allows ranges. Simply seperate two ISO8601 dates with  
a / eg. 1595-11/1596-02.

Regards
Jim

Jim O'Donnell
jim@eatyourgreens.org.uk
http://eatyourgreens.org.uk
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