Subject: Re: Are date ranges half-open?

From: [email-masked]
Date: Wed, 25 Apr 2001 15:32:58 -0400

Eric asked:
>I've always though of the span of time of an event as a half-open
>interval. That is, the event includes the start time but does not include
>the end time -- it ends some infintesimal moment before.

I think we all agree it is...

>In fact, I don't think the spec has anything to say about time
>spans either. Perhaps we should include some text the defines the end 
date
>or time to not be part of the interval?

From 2445, Section 4.6.1 Event Component, p 53 says:

   The "DTSTART" property for a "VEVENT" specifies the inclusive start
   of the event. For recurring events, it also specifies the very first
   instance in the recurrence set. The "DTEND" property for a "VEVENT"
   calendar component specifies the non-inclusive end of the event. For
   cases where a "VEVENT" calendar component specifies a "DTSTART"
   property with a DATE data type but no "DTEND" property, the events
   non-inclusive end is the end of the calendar date specified by the
   "DTSTART" property. For cases where a "VEVENT" calendar component
   specifies a "DTSTART" property with a DATE-TIME data type but no
   "DTEND" property, the event ends on the same calendar date and time
   of day specified by the "DTSTART" property.

Bruce
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Bruce Kahn                                INet: [email-masked]
Iris Associates                          Phone: 978.392.5335
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