Outlook DST (Daylight Saving Time) problem

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LaleX

Member
Outlook version
Outlook 2010 32 bit
Email Account
Hi,

I'm trying to create a meeting event on outlook (using an outlook.com account) through a third party application we're developing. Everything works as expected, except when the "Daylight Saving Time" is effective. In this scenario, when the meeting organizer or invitees receives the e-mail with the invitation, initially the start time and end time show up correctly... but if I send another invitation or wait for few moments, the former invitation start time jumps one hour.

Example:

If the meeting start date is 8:00AM, it becomes 9:00AM.

The meeting ics contains the following "DAYLIGHT" property:

BEGIN:DAYLIGHT

DTSTART:16011020T235959

RRULE:FREQ=YEARLY;BYDAY=3SA;BYMONTH=10

TZOFFSETFROM:-0300

TZOFFSETTO:-0200

END:DAYLIGHT

I compared the ICS files that the outlook stores: the file content before the "one hour jump", and the file content after, and some properties were changed. The following are relevant data that was changed (presumably by Exchange Server):

TZID went from "America/Sao_Paulo" to "SA Eastern Standard Time" (the former is the correct one)

TZOFFSETFROM went from "-0200" to "-3000"

TZOFFSETTO went from "-0200" to "-3000"

We also tried the same thing using a Gmail account (through the Outlook 2010 client) and it behaves correctly. Therefore, i'm suspecting of something related to Exchange Server which might be changing the event.

PS: This issue was verified on Outlook 2007 and 2010 (although I doubt it has any influence whatsoever on this issue).

I appreciate any light on this matter.

Alex
 
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