/***********************************************************************
* GetTimeZoneInformation (KERNEL32.@)
*
* Get information about the current local time zone.
*
* PARAMS
* tzinfo [out] Destination for time zone information.
*
* RETURNS
* TIME_ZONE_ID_INVALID An error occurred
* TIME_ZONE_ID_UNKNOWN There are no transition time known
* TIME_ZONE_ID_STANDARD Current time is standard time
* TIME_ZONE_ID_DAYLIGHT Current time is daylight savings time
*/
DWORD WINAPI GetTimeZoneInformation( LPTIME_ZONE_INFORMATION tzinfo )
{
NTSTATUS status;
status = RtlQueryTimeZoneInformation( (RTL_TIME_ZONE_INFORMATION*)tzinfo );
if ( status != STATUS_SUCCESS )
{
SetLastError( RtlNtStatusToDosError(status) );
return TIME_ZONE_ID_INVALID;
}
return TIME_ZoneID( tzinfo );
}
BOOLEAN
NTAPI
ExRefreshTimeZoneInformation(IN PLARGE_INTEGER CurrentBootTime)
{
LARGE_INTEGER CurrentTime;
NTSTATUS Status;
/* Read time zone information from the registry */
Status = RtlQueryTimeZoneInformation(&ExpTimeZoneInfo);
if (!NT_SUCCESS(Status))
{
/* Failed, clear all data */
RtlZeroMemory(&ExpTimeZoneInfo, sizeof(TIME_ZONE_INFORMATION));
ExpTimeZoneBias.QuadPart = (LONGLONG)0;
ExpTimeZoneId = TIME_ZONE_ID_UNKNOWN;
}
else
{
/* FIXME: Calculate transition dates */
/* Set bias and ID */
ExpTimeZoneBias.QuadPart = ((LONGLONG)(ExpTimeZoneInfo.Bias +
ExpTimeZoneInfo.StandardBias)) *
TICKSPERMINUTE;
ExpTimeZoneId = TIME_ZONE_ID_STANDARD;
}
/* Change it for user-mode applications */
SharedUserData->TimeZoneBias.High1Time = ExpTimeZoneBias.u.HighPart;
SharedUserData->TimeZoneBias.High2Time = ExpTimeZoneBias.u.HighPart;
SharedUserData->TimeZoneBias.LowPart = ExpTimeZoneBias.u.LowPart;
SharedUserData->TimeZoneId = ExpTimeZoneId;
/* Convert boot time from local time to UTC */
KeBootTime.QuadPart += ExpTimeZoneBias.QuadPart;
/* Convert system time from local time to UTC */
do
{
CurrentTime.u.HighPart = SharedUserData->SystemTime.High1Time;
CurrentTime.u.LowPart = SharedUserData->SystemTime.LowPart;
} while (CurrentTime.u.HighPart != SharedUserData->SystemTime.High2Time);
/* Change it for user-mode applications */
CurrentTime.QuadPart += ExpTimeZoneBias.QuadPart;
SharedUserData->SystemTime.LowPart = CurrentTime.u.LowPart;
SharedUserData->SystemTime.High1Time = CurrentTime.u.HighPart;
SharedUserData->SystemTime.High2Time = CurrentTime.u.HighPart;
/* Return success */
return TRUE;
}
