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Home » Kerio User Forums » Kerio Connect » iCal vs Outlook/Exchange invitation time zone broken (Will Implicit Scheduling fix this in 7.2?)
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schwifty

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When a calendar invitation arrives from Exchange 2007 (possibly via Outlook 2003-10), iCal via CalDAV does not handle such time zone information well. Either iCal, Outlook, or Exchange are not handling VTIMEZONE information properly, but regardless of which one is adhering to the specification, it is resulting in the improper time-shifting of events in iCal.

Although Kerio appears to parse out the VTIMEZONE data and compile it into DTEND and DTSTART, it does not do so in a way that is comprehensible to iCal (in 10.6, haven't tested 10.5). Given that Kerio is first receiving the meeting from iCal, the event would already be accepted on the client's iCal and would require the server to update the event to fix it.

1. This is the original .ics attachment that was received by us (CST) as an invitation from outside the company (EST):

METHOD:REQUEST
PRODID:Microsoft Exchange Server 2007
VERSION:2.0
BEGIN:VTIMEZONE
TZID:Eastern Standard Time
BEGIN:STANDARD
DTSTART:16010101T020000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=11
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:16010101T020000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=2SU;BYMONTH=3
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Eastern Standard Time:20110321T143000
DTEND;TZID=Eastern Standard Time:20110321T150000
DTSTAMP:20110321T012947Z

END:VEVENT


2. This is the same event from our webmail calendar, clipped from the webmail ics file. It displays correctly as 1:30-2:00pm (properly shifted one hour for the time zone), seems to have consolidated all of the VTIMEZONE info into DTEND and DTSTART, and works in Entourage 2008 clients:

BEGIN:VEVENT
DTEND;TZID="GMT -0005 (Standart) / GMT -0004 (Daylight)":20110321T150000
DTSTAMP:20110321T012947Z
DTSTART;TZID="GMT -0005 (Standart) / GMT -0004 (Daylight)":20110321T143000

END:VEVENT


3. This event is from iCal's local cache. It displays incorrectly as being from 2:30 to 3:00pm (not shifting from EST to CST like it should) because it does not contain any time zone info, only the raw time and date:

CALSCALE:GREGORIAN
VERSION:2.0
PRODID:-//Apple Inc.//iCal 4.0.4//EN
BEGIN:VEVENT
DTEND:20110321T150000
DTSTAMP:20110321T012947Z
DTSTART:20110321T143000

END:VEVENT


Could Kerio parse invitations like this in such a way that they end up appearing in iCal correctly? Is this an issue that Implicit Scheduling in Kerio 7.2 is supposed to fix?
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schwifty

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In the 7.2 beta 6 release notes this is listed as a known issue:

"iPhone 4.0 (CalDAV account): Calendar event may lose time zone definition if edited."

This sounds like exactly the same problem. Will this issue be fixed for 7.2 release? Will it also fix the same problem iCal has ignoring time zone data?
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MisterH

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I have experienced a similar problem with some invitations appearing in iCal a few hours before the intended time. This only happens with invitations from a few people who report they are using Outlook. Most invitations work correctly. Kerio's tech department responded to me as follows:


On Mar 28, 2011, at 3:11 PM, Kerio Support wrote:

Hi MisterH,

The development team recognized this as a bug we have on file for the TNEF decoder. I have added your ticket to that bug report.

The workaround is to ask the sender to send an invitation in MIME format instead of TNEF. I think this can be done by setting Outlook to use HTML instead of Rich Text for outgoing emails.

The development would also like a copy of the original meeting request from the Kerio Connect Archive folder. Having a copy of the meeting request will help us to improve the TNEF decoder. Do you have the Archive feature enabled?

Best regards,
Jeff Wadlow


I turned TNEF decoding off in Kerio and installed Letter Opener, a Mail plug-in that decodes winmail.dat files. I have done a single test with one of the people who had been sending me errant invitations. The test invitation work as intended. The following are a few links to some of my research along the path to this possible work-around.

Letter Opener: www.restoroot.com/OMiC/en/index.php
winmail.dat: news.office-watch.com/t/n.aspx?a=716
TNEF: www.joshjacob.com/mac-development/tnef.php
script that did not work for this problem: thefragens.com/blog/2008/08/ical-exchange-time-zone-fix-chap ter-2/

Hope this helps.

"Relax, its only ONES and ZEROS!"
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schwifty

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Thanks MisterH, there's a good chance that it might help actually. Unfortunately the meetings are arriving from outside of our org and we'd rather not turn off TNEF decoding globally for now, so it makes it difficult to test, but the bad meeting request did have these headers (all blank values):

X-MS-Has-Attach:
X-MS-TNEF-Correlator:
MIME-Version: 1.0

So perhaps OLE/RTF is indeed in play here. Thanks very much, the next time this happens I'll try to test it further.
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uptimjeff

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This is a critical issue for my clients...
Having invites arrive with the wrong time is a deal-breaker for calendar management.

I can't turn off tnef decoding, it would impact everyone.

I hope we see a quick fix on this issue.
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schwifty

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iCal time zone problems are the only known issue we have seen in our limited deployment of the Apple trifecta. Mail.app has worked well for a long time. Address Book.app is finally functional as of 7.1.4 and the CardDAV fix. If this iCal time zone (tnef?) issue were to be hot-fixed we would have a viable upgrade path from Entourage 2008 right now, not when EWS ships with 7.2 (and is fixed in 7.2.x, etc Razz ).

It is particularly painful/urgent for us because we have many clients with multiple (i.e. external) Exchange accounts, for which Outlook 2011 is already available. Displaying incorrect time info in the calendar is a non-starter, but it's literally the last known issue we have with it before we are finally able to move away from Entourage.
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schwifty

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Kerio Connect 7.1.4 Patch 1 - April 26, 2011

Kerio Connect
- Fixed stability problem in internal decoding module.

Is the "internal decoding module" the winmail.dat decoder? If so we'll be testing it against some known bad events.
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uptimjeff

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I'd also like to know more about this patch.....
I've had to turn OFF tnef decoding at my sites, the clients use a local decoder instead.. less than ideal.

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jlightfoot

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This bug seems like it's come back. Starting 2-3 weeks ago, we began having this problem -- time zone information is being lost when someone updates an invitation. It seems to require an interaction between Outlook and Mac Calendar. Is there a patch for this?
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jlightfoot

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We're using Kerio Connect version 8.3.3377.
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