diff --git a/reactos/ntoskrnl/ex/time.c b/reactos/ntoskrnl/ex/time.c
index 3a08d9d627e..aaec17996c5 100644
--- a/reactos/ntoskrnl/ex/time.c
+++ b/reactos/ntoskrnl/ex/time.c
@@ -1,4 +1,4 @@
-/* $Id: time.c,v 1.24 2004/11/06 16:04:58 ekohl Exp $
+/* $Id: time.c,v 1.25 2004/11/28 12:59:33 ekohl Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -89,7 +89,7 @@ NtSetSystemTime(IN PLARGE_INTEGER UnsafeNewSystemTime,
 			    sizeof(NewSystemTime));
   if (!NT_SUCCESS(Status))
     {
-      return(Status);
+      return Status;
     }
   
   if (UnsafeOldSystemTime != NULL)
@@ -102,10 +102,8 @@ NtSetSystemTime(IN PLARGE_INTEGER UnsafeNewSystemTime,
 		      &TimeFields);
   HalSetRealTimeClock(&TimeFields);
 
-  /* FIXME: set system time */
-#if 0
-  KeSetSystemTime();
-#endif
+  /* Set system time */
+  KiSetSystemTime(&NewSystemTime);
 
   if (UnsafeOldSystemTime != NULL)
     {
@@ -113,10 +111,11 @@ NtSetSystemTime(IN PLARGE_INTEGER UnsafeNewSystemTime,
 			      sizeof(OldSystemTime));
       if (!NT_SUCCESS(Status))
 	{
-	  return(Status);
+          return Status;
 	}
     }
-  return(STATUS_SUCCESS);
+
+  return STATUS_SUCCESS;
 }
 
 
diff --git a/reactos/ntoskrnl/include/internal/ke.h b/reactos/ntoskrnl/include/internal/ke.h
index a5833c0ef3c..a6f43651631 100644
--- a/reactos/ntoskrnl/include/internal/ke.h
+++ b/reactos/ntoskrnl/include/internal/ke.h
@@ -184,6 +184,9 @@ VOID
 STDCALL
 KeFlushCurrentTb(VOID);
 
+VOID
+KiSetSystemTime(PLARGE_INTEGER NewSystemTime);
+
 #endif /* not __ASM__ */
 
 #define MAXIMUM_PROCESSORS      32
diff --git a/reactos/ntoskrnl/ke/timer.c b/reactos/ntoskrnl/ke/timer.c
index e6adef03483..5911f931891 100644
--- a/reactos/ntoskrnl/ke/timer.c
+++ b/reactos/ntoskrnl/ke/timer.c
@@ -1,4 +1,4 @@
-/* $Id: timer.c,v 1.91 2004/11/27 16:57:03 hbirr Exp $
+/* $Id: timer.c,v 1.92 2004/11/28 12:59:00 ekohl Exp $
  *
  * COPYRIGHT:      See COPYING in the top level directory
  * PROJECT:        ReactOS kernel
@@ -821,4 +821,58 @@ KeUpdateSystemTime(
    KeInsertQueueDpc(&ExpireTimerDpc, (PVOID)TrapFrame->Eip, 0);
 }
 
+
+VOID
+KiSetSystemTime(PLARGE_INTEGER NewSystemTime)
+{
+  LARGE_INTEGER OldSystemTime;
+  LARGE_INTEGER DeltaTime;
+  KIRQL OldIrql;
+  PLIST_ENTRY current_entry = NULL;
+  PKTIMER current = NULL;
+
+  ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
+
+  OldIrql = KeAcquireDispatcherDatabaseLock();
+
+  do
+    {
+      OldSystemTime.u.HighPart = SharedUserData->SystemTime.High1Time;
+      OldSystemTime.u.LowPart = SharedUserData->SystemTime.LowPart;
+    }
+  while (OldSystemTime.u.HighPart != SharedUserData->SystemTime.High2Time);
+
+  /* Set the new system time */
+  SharedUserData->SystemTime.LowPart = NewSystemTime->u.LowPart;
+  SharedUserData->SystemTime.High1Time = NewSystemTime->u.HighPart;
+  SharedUserData->SystemTime.High2Time = NewSystemTime->u.HighPart;
+
+  /* Calculate the difference between the new and the old time */
+  DeltaTime.QuadPart = NewSystemTime->QuadPart - OldSystemTime.QuadPart;
+
+  /* Update system boot time */
+  SystemBootTime.QuadPart += DeltaTime.QuadPart;
+
+  /* Update all relative timers */
+  current_entry = RelativeTimerListHead.Flink;
+  ASSERT(current_entry);
+  while (current_entry != &RelativeTimerListHead)
+    {
+      current = CONTAINING_RECORD(current_entry, KTIMER, TimerListEntry);
+      ASSERT(current);
+      ASSERT(current_entry != &RelativeTimerListHead);
+      ASSERT(current_entry->Flink != current_entry);
+
+      current->DueTime.QuadPart += DeltaTime.QuadPart;
+
+      current_entry = current_entry->Flink;
+    }
+
+  KeReleaseDispatcherDatabaseLock(OldIrql);
+
+  /*
+   * NOTE: Expired timers will be processed at the next clock tick!
+   */
+}
+
 /* EOF */