Contains a stream that maps to the persisted format of a TZREG structure, describing the time zone to be used for the start and end time of a recurring appointment or meeting request.

Quick Info

Exposed on: Message objects used for scheduling
Created by: Outlook
Accessed by: Outlook and solution providers
Property type: PT_BINARY
Access type: Read-only


Microsoft Office Outlook 2003, earlier versions of Outlook, and solutions that are based on Collaboration Data Objects (CDO) 1.21 which have not run the calendar update tool by Outlook or Microsoft Exchange Server store the start time and end times of a recurring appointment or meeting request as relative time, and store information of the time zone in which the appointment or meeting request is created in dispidTimeZoneStruct. However, this scheme ignores that over time, time zone rules can change, resulting in some appointments and meetings that users scheduled before the rules change occurring at incorrect times. Users and administrators who are not running Windows Vista or who do not have automatic updates turned on should use the calendar rebasing tools provided by Outlook or Exchange Server to adjust the time of such appointments and meeting requests. For more information about these calendar rebasing tools and APIs that rebase calendars, see About Rebasing Calendars Programmatically for Daylight Saving Time.

To retrieve the value of this property, first use IMAPIProp::GetIDsFromNames to obtain the property tag, and then specify this property tag in IMAPIProp::GetProps to get the value. When calling IMAPIProp::GetIDsFromNames, specify the following values for the MAPINAMEID structure pointed at by the input parameter lppPropNames:

lpGuid: PSETID_Appointment
ulKind: MNID_ID
Kind.lID: dispidTimeZoneStruct

Use the following little endian format when parsing a stream obtained from dispidTimeZoneStruct, or when persisting the TZREG structure to a stream to commit to the dispidTimeZoneStruct binary property.

  long        lBias;           // offset from GMT
long        lStandardBias;   // offset from bias during standard time
long        lDaylightBias;   // offset from bias during daylight time
WORD        wReserved1;      // reserved
SYSTEMTIME  stStandardDate;  // time to switch to standard time
WORD        wReserved2;      // reserved
SYSTEMTIME  stDaylightDate;  // time to switch to daylight time

Note that the reserved WORD members do not map to any component of the TZREG structure. When parsing the persisted form of the structure, they should be ignored.

See Also

Constants for Outlook Named Properties

How to: Parse a Stream from a Binary Property to Read the TZREG Structure

How to: Read Time Zone Properties from an Appointment