- From: Mark Nottingham <mnot@akamai.com>
- Date: Tue, 17 Apr 2001 15:54:09 -0700
- To: Alan Davies <aland@steltor.com>
- Cc: Carl Benkley <cbenkley@mitre.org>, www-rdf-calendar@w3.org
Very much so, thanks!
I'm always in favour of modular standards docs, and it looks like
there might be considerable value in having a spin-off here.
BTW, another recent one is:
http://www.ietf.org/internet-drafts/draft-ietf-impp-datetime-00.txt
Yet another choice...
Cheers,
On Tue, Apr 17, 2001 at 05:04:50PM -0400, Alan Davies wrote:
> Here's some info from the calsch group, I had assumed that
> one of our more eager posters would have provided you with a
> full response earlier...
>
> iCalendar has a RECUR value type, which can express
> quite complex (arguably too complex) recurrences
> using units ranging from seconds to years (including days of
> the week, month, year, etc.), for example "every Sunday in
> January at 8:30 AM and 9:30 AM, every other year":
>
> RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9;BYMINUTE=30
>
> iCalendar also a PERIOD value type, used for durations.
> For more information- http://ietf.org/rfc/rfc2445.txt 4.3.9 and
> 4.3.10
>
> If you prefer XML syntax, there is a draft (which unfortunately
> wasn't renewed, so has expired- I can send you a copy if you like)
> that proposes an iCalendar DTD.
>
> One thing to note is that a simplification of the recurrence rules
> has been recently suggested, as another WG (iptel) wanted to use
> the iCalendar syntax, but needed to be able to test whether a given
> date intersected with a rule in a time linear with the length of the
> rule. See http://ietf.org/internet-drafts/draft-ietf-iptel-cpl-04.txt
> 5.3 and Appendix A. Some posts related to this issue:
> http://www.imc.org/ietf-calendar/mail-archive/msg06890.html
> http://www.imc.org/ietf-calendar/mail-archive/msg06979.html
>
> hope this is of some use...
>
> --Alan
>
>
> At 16:03 2001-04-17 -0400, Carl Benkley wrote:
> >Mark,
> >
> >Your question may be quick, but I doubt there is any quick answer. What
> >you are looking for is a general way of expressing first occurence plus
> >recurring interval (and possibly last occurence) My first guess would be
> >to model it with the full range of possibilities that the data types in
> >XML Schemas would allow. A couple of valid possibilities within this
> >context are "dateTime" plus "duration" (duration treated as a recurring
> >interval), and "date" plus "gDay". Unfortunately, the folks that
> >brought us XML Schemas and the Gregorian ("g") date datatypes didn't
> >give us a day-of-the-week, which seems critical to what you want to do.
> >You could of course make up a dayOfWeek datatype.
> >
> >Also, I'm wondering if you are concerned only with events that happen in
> >an instant of time. Modeling events of non-zero duration obviously
> >requires some way of modeling that duration.
> >
> >Carl Benkley
> >Lead Information Systems Engineer
> >MITRE Corporation
> >
> >
> >Mark Nottingham wrote:
> > >
> > > Hello,
> > >
> > > I sent the attached message to the IETF calsch WG a few days ago, and
> > > haven't gotten anything back. Does anyone here have strong feelings
> > > about this, and/or a reference?
> > >
> > > I'd like to see something moving towards a (hopefully short) standard
> > > here, as there are a number of different application domains. Or
> > > perhaps I'm just missing one that already exists (crosses fingers)?
> > >
> > > Cheers,
> > >
> > > --
> > > Mark Nottingham, Research Scientist
> > > Akamai Technologies (San Mateo, CA USA)
> > >
> > > ------------------------------------------------------------------------
> > >
> > > Subject: representing scheduled events
> > > Date: Sun, 15 Apr 2001 14:01:49 -0700
> > > From: Mark Nottingham <mnot@akamai.com>
> > > To: ietf-calendar@imc.org
> > >
> > > Hello,
> > >
> > > Just a quick question. I've seen several fields where it's desireable
> > > to model a scheduled event and then represent it in some form (XML or
> > > a simple string, usually).
> > >
> > > For example, I'd want to model and express:
> > > - "Every Tueday at 6pm"
> > > - "The first Monday of the month at noon"
> > > - "Every other day at midnight"
> > >
> > > Possible uses include for HTTP cache freshness, recurring events in
> > > RSS news feeds, and policy updates for things like P3P. In general,
> > > I'm talking about representing a publication schedule.
> > >
> > > Does calsch have a solution for this, or any thoughts that would
> > > point an effort to develop such a thing in the right direction?
> > >
> > > Cheers,
> > >
> > > --
> > > Mark Nottingham, Research Scientist
> > > Akamai Technologies (San Mateo, CA USA)
--
Mark Nottingham, Research Scientist
Akamai Technologies (San Mateo, CA USA)
Received on Tuesday, 17 April 2001 18:54:51 UTC