GetTimeZoneInformation Function (Windows)

GetTimeZoneInformation Function

Retrieves the current time zone settings. These settings control the translations between Coordinated Universal Time (UTC) and local time.

To support boundaries for daylight saving time that change from year to year, use the GetDynamicTimeZoneInformation or GetTimeZoneInformationForYear function.

Syntax

C++

DWORD WINAPI GetTimeZoneInformation(
  __out  LPTIME_ZONE_INFORMATION lpTimeZoneInformation
);

Parameters

lpTimeZoneInformation [out]: A pointer to a TIME_ZONE_INFORMATION structure to receive the current settings.

Return Value

If the function succeeds, it returns one of the following values.

Return code/value	Description
TIME_ZONE_ID_UNKNOWN 0	Daylight saving time is not used in the current time zone, because there are no transition dates or automatic adjustment for daylight saving time is disabled.
TIME_ZONE_ID_STANDARD 1	The system is operating in the range covered by the StandardDate member of the TIME_ZONE_INFORMATION structure.
TIME_ZONE_ID_DAYLIGHT 2	The system is operating in the range covered by the DaylightDate member of the TIME_ZONE_INFORMATION structure.

If the function fails for other reasons, such as an out of memory error, it returns TIME_ZONE_ID_INVALID. To get extended error information, call GetLastError.

Remarks

All translations between UTC time and local time are based on the following formula:

UTC = local time + bias

The bias is the difference, in minutes, between UTC time and local time.

Examples

For an example, see SetTimeZoneInformation.

Requirements

Minimum supported client	Windows 2000 Professional
Minimum supported server	Windows 2000 Server
Header	Winbase.h (include Windows.h)
Library	Kernel32.lib
DLL	Kernel32.dll