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Consider the following scenario:

  • A Microsoft Exchange Server 2010 mailbox user receives a Simple Mail Transfer Protocol (SMTP) message that contains a recurring iCalendar message part.

  • The recurring iCalendar message part contains an excepted occurrence that is defined by the EXDATE property.

  • The DTSTART property and the EXDATE property are in different time zones.

In this scenario, the occurrence is not excluded from the recurring iCalendar message.

For example, you create the following Recurring Rule (RRULE)-based appointment. The properties in this appointment have the following characteristics:

  • The DTSTART property uses the "Central Europe Standard Time" time zone.

  • The first EXDATE property uses the same time zone as the DTSTART property (through the omission of a specific time zone).

  • The second EXDATE property uses the "Zulu" time zone (denoted by the "Z" suffix).

  • The third EXDATE property uses the "Pacific Standard Time" time zone.

DTSTART;TZID=Central Europe Standard Time:20091212T104700
DTEND;TZID=Central Europe Standard Time:20091212T111700
EXDATE;TZID=Pacific Standard Time:20100712T004700,20100912T004700

In this example, when you view the calendar instances from OWA, Outlook 2007, or Outlook 2010, you see that the EXDATE instances in which the DTSTART property and the EXDATE properties are in different time zones are not deleted. However, all the EXDATE instances should be deleted.


This issue occurs because the EXDATE property is not executed when the DTSTART property and the EXDATE property are in different time zones.


To resolve this issue, install the following update rollup:

2425179 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 1


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about the EXDATE property, visit the following Microsoft website:

General more information about the EXDATE propertyFor more information about the DTSTART property, visit the following Microsoft website:

General information about the DTSTART property

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