Subject: RE: Duration: Does 1 day == 24 hours?

From: [email-masked]
Date: Wed, 28 Mar 2001 10:51:53 -0600

> John Stracke wrote:
 
> This thread is extremely surprising to me.  To me, it's 
> obvious that a duration
> is a scalar value that is equivalent to some number of 
> seconds.  
I think you are missing something here. You need to go back and review the
DURATION specification. It is based on the ISO 8601 date/time standard
ability to specify either a duration of years, months, weeks, days or the
more precise hours, minutes, seconds, partial seconds.

As such, if you use the duration of a day you need to utilize the date
scale. If an event has a duration of one day, then I take the date-time form
of the DSTART (per the original example) and the "scalarity" would be the
day of the year specified in the date component.

>To take a
> duration of one day and turn it into 15 hours, or 9 hours, or 
> something, just
> does not make sense to me.  (The "sensible duration" 
> approach, in particular,
> is fraught with peril; who decides what's sensible? The 
> modern 8-hour work day
> is a historical artifact left over from the "share the work" 
> sentiment of the
> Great Depression.)
> 

What is the point here? The problem with the example given is that we have
tried to take the P1D and turn it into a PTnHnMnS format to align with the
date-time DTSTART value. This is a problem. The DTSTART is good for
identifying an absolute start of the event. But the DURATION:P1D value means
that the end will have to be figured off of the lesser specific value of
days. The DTEND equivalent SHOULD BE the end of the calendar day specified
in the DTSTART. 

This approach is KISS all the way. It simplifies the problem and allows for
a less complex solution.

The same approach needs to be taken if the duration was a year. The DTEND is
the last second on the last day of the year specified by the DTSTART. This
would also work with week. ISO 8601 says that a week is a seven day period
(by default starts on Monday). So, the end of the week is the following
Sunday (with default start of the week).

This approach may seem bizarre but I believe it is more rationale than that
proposed by you and Alan.

-- Frank

---

From: John Stracke <[email-masked]>
Date: Wed, 28 Mar 2001 12:51:24 -0500

[email-masked] wrote:

> > To me, it's
> DURATION specification

I did.  As near as I can tell, RFC-2445 does not say *anything* the semantics
of DURATION, only its syntax.

> scale.

Can you point to the text that says this?

--
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