PidLidTimeZoneStruct Canonical Property

Last modified: July 23, 2011

Applies to: Outlook

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

Associated properties:


Property set:


Long ID (LID):


Data type:




Microsoft Office Outlook 2003, earlier versions of Outlook, and applications that are based on Collaboration Data Objects (CDO) 1.21 whose users have not run the calendar update tool provided by Outlook or Exchange Server store the start time and end time of a recurring appointment or meeting request as relative time, and store the time zone where 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 changed and occur 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 that are 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

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        wStandardYear;      // matches the stStandardDate’s wYear member
SYSTEMTIME  stStandardDate;  // time to switch to standard time
WORD        wDaylightYear;      // matches the stDaylightDate’s wYear field
SYSTEMTIME  stDaylightDate;  // time to switch to daylight time

This property is set on a recurring series to specify time-zone information, and specifies how to convert time fields between local time and Coordinated Universal Time (UTC).

Protocol Specifications


Provides property set definitions and references to related Exchange Server protocol specifications.


Specifies the properties and operations for appointment, meeting request, and response messages.

Header Files


Provides data type definitions.