Subject: RFC 2445: Question on interaction of RRULE COUNT and Timezones

From: Jonathan Lennox <[email-masked]>
Date: Tue, 3 Oct 2000 16:47:40 -0400 (EDT)

In an RRULE with a COUNT parameter, is the recurrence count supposed to take
into account repeated or dropped times due to time zone shifts?
Specifically, is the full enumeration of

        DTSTART;TZID=US-Eastern:20001028T013000
        RRULE:FREQ=DAILY;BYHOUR=1;COUNT=4

Sat, Oct 28 2000, 01:30:00 EDT
Sun, Oct 29 2000, 01:30:00 EDT
Sun, Oct 29 2000, 01:30:00 EST (1 hour later)
Mon, Oct 30 2000, 01:30:00 EST

or is there an occurence on October 31 as well (as you would expect in the
absence of a DST shift)?

Similarly, what happens for

        DTSTART;TZID=US-Eastern:20000401T023000
        RRULE:FREQ=DAILY;BYHOUR=2;COUNT=4

(the EST - EDT transition)?  Is April 2nd skipped?  Does it matter whether
the duration is more or less than a half hour?

-- 
Jonathan Lennox
[email-masked]

---

From: Damon Chaplin <[email-masked]>
Date: Mon, 09 Oct 2000 01:48:19 +0100

> or is there an occurence on October 31 as well (as you would expect in the

I'd be surprised if there were 2 events on Oct 29. It is supposed to be a DAILY
recurrence.

Though I don't know which of the 2 occurrences on Oct 29 should be used.
Anyone know if the spec covers this?
I'd probably go for the first time (EDT).

> the duration is more or less than a half hour?

That's an interesting question too.
I'd guess that if the occurrence disappears completely you skip it,
otherwise it gets truncated.

Damon

---

From: John Stracke <[email-masked]>
Date: Mon, 09 Oct 2000 10:14:12 -0400

> I'd probably go for the first time (EDT).

So would I, because people who are staying up until 1:30AM are probably going to
say, "OK, 1:30 is two hours past 11:30".

--
/==============================================================\
|John Stracke    | http://www.ecal.com |My opinions are my own.|
|Chief Scientist |=============================================|
|eCal Corp.      |"Chris is the most self-effacing guy I know."|
[email-masked]|"Well, I'm not *that* good at it."           |
\==============================================================/