diff --git a/dlls/ntdll/time.c b/dlls/ntdll/time.c
index 4d3c8afae65..96b8ceab3bc 100644
--- a/dlls/ntdll/time.c
+++ b/dlls/ntdll/time.c
@@ -228,44 +228,6 @@ BOOLEAN WINAPI RtlTimeFieldsToTime(
         return TRUE;
 }
 
-/***********************************************************************
- *       TIME_GetBias [internal]
- *
- * Helper function calculates delta local time from UTC. 
- *
- * PARAMS
- *   utc [I] The current utc time.
- *   pdaylight [I] Local daylight.
- *
- * RETURNS
- *   The bias for the current timezone.
- */
-static LONG TIME_GetBias(void)
-{
-    static time_t last_utc;
-    static LONG last_bias;
-    LONG ret;
-    time_t utc;
-
-    utc = time( NULL );
-
-    RtlEnterCriticalSection( &TIME_tz_section );
-    if (utc != last_utc)
-    {
-        RTL_DYNAMIC_TIME_ZONE_INFORMATION tzi;
-        int is_dst = init_tz_info( &tzi );
-
-	last_utc = utc;
-        last_bias = tzi.Bias;
-        last_bias += is_dst ? tzi.DaylightBias : tzi.StandardBias;
-        last_bias *= SECSPERMIN;
-    }
-
-    ret = last_bias;
-
-    RtlLeaveCriticalSection( &TIME_tz_section );
-    return ret;
-}
 
 /******************************************************************************
  *        RtlLocalTimeToSystemTime [NTDLL.@]
@@ -283,12 +245,12 @@ static LONG TIME_GetBias(void)
 NTSTATUS WINAPI RtlLocalTimeToSystemTime( const LARGE_INTEGER *LocalTime,
                                           PLARGE_INTEGER SystemTime)
 {
-    LONG bias;
+    SYSTEM_TIMEOFDAY_INFORMATION info;
 
     TRACE("(%p, %p)\n", LocalTime, SystemTime);
 
-    bias = TIME_GetBias();
-    SystemTime->QuadPart = LocalTime->QuadPart + bias * (LONGLONG)TICKSPERSEC;
+    NtQuerySystemInformation( SystemTimeOfDayInformation, &info, sizeof(info), NULL );
+    SystemTime->QuadPart = LocalTime->QuadPart + info.TimeZoneBias.QuadPart;
     return STATUS_SUCCESS;
 }
 
@@ -308,12 +270,12 @@ NTSTATUS WINAPI RtlLocalTimeToSystemTime( const LARGE_INTEGER *LocalTime,
 NTSTATUS WINAPI RtlSystemTimeToLocalTime( const LARGE_INTEGER *SystemTime,
                                           PLARGE_INTEGER LocalTime )
 {
-    LONG bias;
+    SYSTEM_TIMEOFDAY_INFORMATION info;
 
     TRACE("(%p, %p)\n", SystemTime, LocalTime);
 
-    bias = TIME_GetBias();
-    LocalTime->QuadPart = SystemTime->QuadPart - bias * (LONGLONG)TICKSPERSEC;
+    NtQuerySystemInformation( SystemTimeOfDayInformation, &info, sizeof(info), NULL );
+    LocalTime->QuadPart = SystemTime->QuadPart - info.TimeZoneBias.QuadPart;
     return STATUS_SUCCESS;
 }
 
diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index 68de16b7e5b..1d81e8a04f9 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -1690,10 +1690,18 @@ NTSTATUS WINAPI NtQuerySystemInformation( SYSTEM_INFORMATION_CLASS class,
 
     case SystemTimeOfDayInformation:
     {
+        struct tm *tm;
+        time_t now;
         SYSTEM_TIMEOFDAY_INFORMATION sti = {{{ 0 }}};
 
-        /* liKeSystemTime, liExpTimeZoneBias, uCurrentTimeZoneId */
-        sti.liKeBootTime.QuadPart = server_start_time;
+        sti.BootTime.QuadPart = server_start_time;
+        now = time( NULL );
+        tm = gmtime( &now );
+        sti.TimeZoneBias.QuadPart = mktime( tm ) - now;
+        tm = localtime( &now );
+        if (tm->tm_isdst) sti.TimeZoneBias.QuadPart -= 3600;
+        sti.TimeZoneBias.QuadPart *= TICKSPERSEC;
+        NtQuerySystemTime( &sti.SystemTime );
 
         if (size <= sizeof(sti))
         {
diff --git a/dlls/wbemprox/builtin.c b/dlls/wbemprox/builtin.c
index 466611721ab..2ff3131936d 100644
--- a/dlls/wbemprox/builtin.c
+++ b/dlls/wbemprox/builtin.c
@@ -3275,7 +3275,7 @@ static WCHAR *get_lastbootuptime(void)
     if (!(ret = heap_alloc( 26 * sizeof(WCHAR) ))) return NULL;
 
     NtQuerySystemInformation( SystemTimeOfDayInformation, &ti, sizeof(ti), NULL );
-    RtlTimeToTimeFields( &ti.liKeBootTime, &tf );
+    RtlTimeToTimeFields( &ti.BootTime, &tf );
     swprintf( ret, 26, L"%04u%02u%02u%02u%02u%02u.%06u+000", tf.Year, tf.Month, tf.Day, tf.Hour, tf.Minute,
               tf.Second, tf.Milliseconds * 1000 );
     return ret;
diff --git a/include/winternl.h b/include/winternl.h
index 3ff15f28c15..ae41af85b3f 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -1482,10 +1482,10 @@ typedef struct _SYSTEM_PERFORMANCE_INFORMATION {
 
 typedef struct _SYSTEM_TIMEOFDAY_INFORMATION {
 #ifdef __WINESRC__
-    LARGE_INTEGER liKeBootTime;
-    LARGE_INTEGER liKeSystemTime;
-    LARGE_INTEGER liExpTimeZoneBias;
-    ULONG uCurrentTimeZoneId;
+    LARGE_INTEGER BootTime;
+    LARGE_INTEGER SystemTime;
+    LARGE_INTEGER TimeZoneBias;
+    ULONG TimeZoneId;
     ULONG Reserved;
     ULONGLONG BootTimeBias;
     ULONGLONG SleepTimeBias;
diff --git a/programs/taskmgr/perfdata.c b/programs/taskmgr/perfdata.c
index 3b5997d759f..d81ab102482 100644
--- a/programs/taskmgr/perfdata.c
+++ b/programs/taskmgr/perfdata.c
@@ -199,7 +199,7 @@ void PerfDataRefresh(void)
         /*  CurrentValue = NewValue - OldValue */
         dbIdleTime = Li2Double(SysPerfInfo.IdleTime) - Li2Double(liOldIdleTime);
         dbKernelTime = CurrentKernelTime - OldKernelTime;
-        dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);
+        dbSystemTime = Li2Double(SysTimeInfo.SystemTime) - Li2Double(liOldSystemTime);
 
         /*  CurrentCpuIdle = IdleTime / SystemTime */
         dbIdleTime = dbIdleTime / dbSystemTime;
@@ -212,7 +212,7 @@ void PerfDataRefresh(void)
 
     /* Store new CPU's idle and system time */
     liOldIdleTime = SysPerfInfo.IdleTime;
-    liOldSystemTime = SysTimeInfo.liKeSystemTime;
+    liOldSystemTime = SysTimeInfo.SystemTime;
     OldKernelTime = CurrentKernelTime;
 
     /* Determine the process count