[whatwg] Historic dates in HTML5

Greg Houston gregory.houston at gmail.com
Thu Mar 5 07:17:32 PST 2009

On Wed, Mar 4, 2009 at 5:29 PM, Jim O'Donnell <jim at eatyourgreens.org.uk> wrote:
> This then leads to a
> situation where some dates on the web can be marked up, semantically, as
> dates but others cannot, which seems somewhat ridiculous really.

I imagine most teachers and students marking up a timeline would come
to the same conclusion, though if my understanding is correct you can
use the time tag for any date, it is the datetime attribute of the
time tag that has this particular limitation. Someone correct me if I
am wrong.

If you Google "HTML5 time" the first result is a W3Schools page. It
gives these two examples:

We open at <time>10:00</time> every morning.

I have a date on <time datetime="2008-02-14">Valentines day</time>

There is no mention that the datetime attribute's year must be between
1 and 9999, and if it did, I think the average person's first thought
would be, "That's weird".

Despite that, here are a couple workarounds that I think are valid:

<time data-datetime="March 5th, 205 b.c.">Something happened</time>

On <time>March 5th, 205 b.c.</time>Something happened.

In the first example, the data-datetime would be for internal use only.

Personally, I think it would be an improvement to the datetime
attribute if it was valid for at least -9999 - 9999:

<p> ... For these events to take place within a three week or so
period is simply impossible. The <time
datetime="-0004-03-13">eclipse</time> cannot be the one written in the
records of Josephus.</p>

Potentially relevant:


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