Re: Date/time tag?? (Erik Ostrom)
From: (Erik Ostrom)
Message-id: <>
Date: Mon, 2 Aug 93 19:23:18 +0100
In-reply-to: <> (message from Marc VanHeyningen on Mon, 02 Aug 1993 13:09:04 -0500)
Subject: Re: Date/time tag?? 
Status: RO
   - Dates frequently represent bounded intervals rather than a single
     point in time.  Should there be a way to represent "from 3:00 until
     8:00 PDT on 30 Nov 95" in these?

   - Dates vary in terms of their quantity of significant "terms"; e.g.
     "November, 1993" should be representable and it's certainly not the
     same as "1 Nov 1993 00:00:00 GMT".

So, suppose we allow for leaving out sections:

   <date at="1993">1993</date>
   <date at="Nov 1993">this month</date>
   <date at="1 Nov 1993">the first of November, 1993</date>
   <date at="1 Nov 1993 00:00:00">midnight</date>

Length of field is enough to distinguish between these.

I think we could consider this a special case of your first point:

   <date at="1 May 1993">Mayday</date>

is in some sense the same as

   <date at="1 May 1993 00:00:00" until="2 May 1993 00:00:00">Mayday</date>

On the other hand, this looks both ugly and ambiguous to me at first glance.

I like the "at" and "until" attributes as an answer to the question of
intervals--short names are nice.  Would these cause problems?

   - Marc


P.S. While we're on the subject of things it would be nice to be able to
indicate, "the third Monday of each month" or "at 3:00 daily" are a kind of
date that comes up fairly often--repeating events.  I don't know how
complicated we want to make this, though.