[whatwg] Issues relating to the syntax of dates and times

[Pentasis]

Ian Hickson wrote:

> While I could see that maybe one day there'd be a use case for <time> that
> would need historical dates, I really think that we'd have to tackle other
> calendars in use today before looking at calendars that aren't in use
> anymore. So I'd rather punt this for now.

While it is true that there are to many factors to take into account 
regarding which calendar, which era, etc.
I can also imagine, (just brainstorming here) if I look at this example in 
the spec:
<p>We stopped talking at <time datetime="2006-09-24 05:00 -7">5am the next 
morning</time>.</p>
This means I should also mark up something like this:
<p>It was <time datetime="???">5 seconds after the big bang</time>.</p>

There are more factors to take into consideration in this example than just 
calendars.
So... Wouldn't it be far more efficient and convinient to have a 
construction by which we can set a "base-date/time"? (something like the 
base-url-thing). That way you can set the date/time to anything at all based 
on a reference-setting. And this reference setting could be anything 
(another calendar, a specific point in time (or perhaps even time-space) or 
a relative reference. I don't think this would have to be dealt with by the 
UA but can be done by scripting.

Bert