RE: Recurring Anniversary Instances?

[Bruce_Kahn@xxxxxxxx]

Frank wrote:
>No, this is an error UNLESS the semantics are that when this occurs, it is a short-hand for >"take the time portion of the date/time" from the original DTSTART and DTEND. This makes >sense to me. For example, define a -T080000Z to -T090000Z meeting (a soiree for us >US-Eastern time zone folks ;-) ) event that is augmented with a RDATE property that >specifies 5 other dates. The interpretation is that these 5 other occurrences are at the >same start/end as the first occurrence. 
>
>Other wise, there appears to be a value type mismatching here also introduces this hybrid >event that is both a traditional appointment and a day-long event. Too weird.

Before hopping into this exchange I would like to get some group clarification/acceptance of something:

Is DTSTART;VALUE=DATE:19990730 equivalent to DTSTART;VALUE=DATE-TIME:19990730T000000Z?

Is DTEND;VALUE=DATE:19990730 equivalent to DTEND;VALUE=DATE-TIME:19990730T235959Z (or should that be DTEND;VALUE=DATE-TIME:19990801T000000Z since its "non-inclusive")?

RFC 2445 has only the following relevant text (for DTSTART):

   The "VEVENT" is also the calendar component used to specify an
   anniversary or daily reminder within a calendar. These events have a
   DATE value type for the "DTSTART" property instead of the default
   data type of DATE-TIME. If such a "VEVENT" has a "DTEND" property, it
   MUST be specified as a DATE value also. The anniversary type of
   "VEVENT" can span more than one date (i.e, "DTEND" property value is
   set to a calendar date after the "DTSTART" property value).

   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. [Snip]

4.8.2.4 Date/Time Start

   [Snip]

   Value Type: The default value type is DATE-TIME. The time value MUST
   be one of the forms defined for the DATE-TIME value type. The value
   type can be set to a DATE value type.

   [Snip]

   Description: Within the "VEVENT" calendar component, this property
   defines the start date and time for the event. The property is
   REQUIRED in "VEVENT" calendar components. Events can have a start
   date/time but no end date/time. In that case, the event does not take
   up any time.

There is no explicit declaration of what the start (or end) time default to in the VALUE=DATE cases.   Before continuing Id like to get concensus (or murmers)...

BTW: One potential example of Dans case is an IETF meeting.  It could be "a repeating all day" entry on my calendar for Monday thru Thursday and only "half a day" on Friday (using an RDATE;VALUE=PERIOD:...).  (Yes, your pending counter example of "a repeating 9AM-6PM" entry for Monday thru Thursday and 9AM-12PM Friday is another way to describe the same thing; its all in how the CU wants to treat it!)

Bruce
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