TIME_ZONE_INFORMATION

The TIME_ZONE_INFORMATION structure specifies information specific to the time zone.

typedef struct _TIME_ZONE_INFORMATION { // tzi 
    LONG       Bias; 
    WCHAR      StandardName[ 32 ]; 
    SYSTEMTIME StandardDate; 
    LONG       StandardBias; 
    WCHAR      DaylightName[ 32 ]; 
    SYSTEMTIME DaylightDate; 
    LONG       DaylightBias; 
} TIME_ZONE_INFORMATION; 
 

Members

Bias

Specifies the current bias, in minutes, for local time translation on this computer. The bias is the difference, in minutes, between Coordinated Universal Time (UTC) and local time. All translations between UTC and local time are based on the following formula:

UTC = local time + bias 
 

This member is required.

StandardName

Specifies a null-terminated string associated with standard time on this operating system. For example, this parameter could contain "EST" to indicate Eastern Standard Time. This string is not used by the operating system, so anything stored there by using the SetTimeZoneInformation function is returned unchanged by the GetTimeZoneInformation function. This string can be empty.

StandardDate

Specifies a SYSTEMTIME structure that contains a date and local time when the transition from daylight time to standard time occurs on this operating system. If this date is not specified, the wMonth member in the SYSTEMTIME structure must be zero. If this date is specified, the DaylightDate value in the TIME_ZONE_INFORMATION structure must also be specified.

This member supports two date formats. Absolute format specifies an exact date and time when standard time begins. In this form, the wYear, wMonth, wDay, wHour, wMinute, wSecond, and wMilliseconds members of the SYSTEMTIME structure are used to specify an exact date.

Day-in-month format is specified by setting the wYear member to zero, setting the wDayOfWeek member to an appropriate weekday, and using a wDay value in the range 1 through 5 to select the correct day in the month. Using this notation, the first Sunday in April can be specified, as can the last Thursday in October (5 is equal to "the last").

StandardBias

Specifies a bias value to be used during local time translations that occur during standard time. This member is ignored if a value for the StandardDate member is not supplied.

This value is added to the value of the Bias member to form the bias used during standard time. In most time zones, the value of this member is zero.

DaylightName

Specifies a null-terminated string associated with daylight time on this operating system. For example, this parameter could contain "PDT" to indicate Pacific Daylight Time. This string is not used by the operating system, so anything stored there by using the SetTimeZoneInformation function is returned unchanged by the GetTimeZoneInformation function. This string can be empty.

DaylightDate

Specifies a SYSTEMTIME structure that contains a date and local time when the transition from standard time to daylight time occurs on this operating system. If this date is not specified, the wMonth member in the SYSTEMTIME structure must be zero. If this date is specified, the StandardDate value in the TIME_ZONE_INFORMATION structure must also be specified. This member supports the absolute and day-in-month time formats described for the StandardDate member.

DaylightBias

Specifies a bias value to be used during local time translations that occur during daylight time. This member is ignored if a value for the DaylightDate member is not supplied.

This value is added to the value of the Bias member to form the bias used during daylight time. In most time zones, the value of this member is – 60.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winbase.h.

See Also

Time Overview, Time Structures, GetTimeZoneInformation, SetTimeZoneInformation, SYSTEMTIME