diff --git a/reactos/ntoskrnl/ex/time.c b/reactos/ntoskrnl/ex/time.c
index 9e52aef6b28..ff4ab2e9d75 100644
--- a/reactos/ntoskrnl/ex/time.c
+++ b/reactos/ntoskrnl/ex/time.c
@@ -45,7 +45,9 @@ NtSetSystemTime (
 	IN	PLARGE_INTEGER	NewSystemTime	OPTIONAL
 	)
 {
-	UNIMPLEMENTED;
+        HalSetRealTimeClock ((PTIME)SystemTime);
+//        UNIMPLEMENTED;
+        return STATUS_SUCCESS;
 }
 
 
diff --git a/reactos/ntoskrnl/hal/x86/time.c b/reactos/ntoskrnl/hal/x86/time.c
index ea478d75abf..80b7fdb4e93 100644
--- a/reactos/ntoskrnl/hal/x86/time.c
+++ b/reactos/ntoskrnl/hal/x86/time.c
@@ -22,19 +22,43 @@
 #define NDEBUG
 #include <internal/debug.h>
 
-/* FUNCTIONS *****************************************************************/
+/* MACROS and CONSTANTS ******************************************************/
 
 /* macro BCD_INT : convert bcd to int */
-#define BCD_INT(bcd) ( ((bcd &0xf0)>>4)*10+(bcd &0x0f) )
+#define BCD_INT(bcd) ( ((bcd & 0xf0) >> 4) * 10 + (bcd &0x0f) )
 
-void HalQueryRealTimeClock(PTIME_FIELDS pTime)
+/* macro INT_BCD : convert int to bcd */
+#define INT_BCD(int) ( ((int / 10) << 4) + (int % 10) )
+
+
+#define RTC_REGISTER_A   0x0A
+#define   RTC_REG_A_UIP  0x80  /* Update In Progress bit */
+
+
+/* FUNCTIONS *****************************************************************/
+
+VOID
+HalQueryRealTimeClock(PTIME_FIELDS pTime)
 {
 //FIXME : wait RTC ok?
+        UCHAR uip;  // Update In Progress
+#if 0
   do
   {
    outb(0x70,0);
    pTime->Second=BCD_INT(inb(0x71));
   } while(pTime->Second>60);
+#endif
+
+  do
+  {
+   outb(0x70, RTC_REGISTER_A);
+   uip = inb(0x71) & RTC_REG_A_UIP;
+  } while(uip);
+
+  outb(0x70,0);
+  pTime->Second=BCD_INT(inb(0x71));
+
   outb(0x70,2);
   pTime->Minute=BCD_INT(inb(0x71));
   outb(0x70,4);
@@ -49,10 +73,54 @@ void HalQueryRealTimeClock(PTIME_FIELDS pTime)
   pTime->Year=BCD_INT(inb_p(0x71));
   if(pTime->Year>80) pTime->Year +=1900;
   else pTime->Year +=2000;
+
+#if 0
+        /* Century */
+        outb_p(0x70,0x32);
+        pTime->Year += BCD_INT(inb_p(0x71)) * 100;
+#endif
+
   pTime->Milliseconds=0;
 }
 
 
-void HalSetRealTimeClock(PTIME_FIELDS pTime)
+VOID
+HalSetRealTimeClock(PTIME_FIELDS pTime)
 {
+        UCHAR uip;  // Update In Progress
+
+        do
+        {
+                outb(0x70,0xA);
+                uip = inb(0x71) & RTC_REG_A_UIP;
+        } while(uip);
+
+
+        outb(0x70,0);
+        outb(0x71, INT_BCD(pTime->Second));
+
+        outb(0x70,2);
+        outb(0x71, INT_BCD(pTime->Minute));
+
+        outb(0x70,4);
+        outb(0x71, INT_BCD(pTime->Hour));
+
+        outb(0x70,6);
+        outb(0x71, INT_BCD(pTime->Weekday));
+
+        outb(0x70,7);
+        outb(0x71, INT_BCD(pTime->Day));
+
+        outb(0x70,8);
+        outb(0x71, INT_BCD(pTime->Month));
+
+        outb_p(0x70,9);
+        outb(0x71, INT_BCD(pTime->Year % 100));
+
+
+        /* Century */
+#if 0
+        outb_p(0x70,0x32);
+        outb(0x71, INT_BCD(pTime->Year / 100));
+#endif
 }
diff --git a/reactos/ntoskrnl/ntoskrnl.def b/reactos/ntoskrnl/ntoskrnl.def
index ae1277033f2..98bf8d89512 100644
--- a/reactos/ntoskrnl/ntoskrnl.def
+++ b/reactos/ntoskrnl/ntoskrnl.def
@@ -1,4 +1,4 @@
-; $Id: ntoskrnl.def,v 1.19 1999/10/21 11:10:26 ekohl Exp $
+; $Id: ntoskrnl.def,v 1.20 1999/10/24 17:52:17 ekohl Exp $
 ;
 ; reactos/ntoskrnl/ntoskrnl.def
 ;
@@ -154,6 +154,7 @@ NtQueryInformationProcess@20
 NtQueryInformationToken@20
 ;NtQueryOleDirectoryFile@ <--- ?
 NtQuerySecurityObject@20
+NtQuerySystemTime@4
 NtQueryVolumeInformationFile@20
 NtReadFile@36
 ;NtRequestPort@8
@@ -165,6 +166,7 @@ NtSetInformationFile@20
 NtSetInformationProcess@16
 NtSetInformationThread@16
 NtSetSecurityObject@12
+NtSetSystemTime@8
 NtUnlockFile@20
 ;NtVdmControl@8 <--- ?
 NtWaitForSingleObject@12
@@ -183,7 +185,11 @@ RtlLargeIntegerAdd
 RtlLargeIntegerGreaterThan
 RtlLargeIntegerShiftRight
 RtlMoveMemory
+RtlSecondsSince1970ToTime
+RtlSecondsSince1980ToTime
 RtlTimeFieldsToTime
+RtlTimeToSecondsSince1970
+RtlTimeToSecondsSince1980
 RtlTimeToTimeFields
 RtlZeroMemory
 ZwAccessCheckAndAuditAlarm@44
@@ -239,6 +245,7 @@ ZwQuerySection@20
 ZwQuerySecurityObject@20
 ZwQuerySymbolicLinkObject@12
 ZwQuerySystemInformation@16
+ZwQuerySystemTime@4
 ZwQueryValueKey@24
 ZwQueryVolumeInformationFile@20
 ZwReadFile@36
@@ -389,7 +396,7 @@ HalSetBusDataByOffset
 HalSetDisplayParameters
 ;HalSetEnvironmentVariable
 ;HalSetProfileInterval
-;HalSetRealTimeClock
+HalSetRealTimeClock
 ;HalSetTimeIncrement
 ;HalStartNextProcessor
 ;HalStartProfileInterrupt
diff --git a/reactos/ntoskrnl/ntoskrnl.edf b/reactos/ntoskrnl/ntoskrnl.edf
index dbe97a18172..c330fb2797a 100644
--- a/reactos/ntoskrnl/ntoskrnl.edf
+++ b/reactos/ntoskrnl/ntoskrnl.edf
@@ -1,4 +1,4 @@
-; $Id: ntoskrnl.edf,v 1.7 1999/10/21 11:10:26 ekohl Exp $
+; $Id: ntoskrnl.edf,v 1.8 1999/10/24 17:52:17 ekohl Exp $
 ;
 ; reactos/ntoskrnl/ntoskrnl.def
 ;
@@ -154,6 +154,7 @@ NtQueryInformationProcess=NtQueryInformationProcess@20
 NtQueryInformationToken=NtQueryInformationToken@20
 ;NtQueryOleDirectoryFile@ <--- ?
 NtQuerySecurityObject=NtQuerySecurityObject@20
+NtQuerySystemTime=NtQuerySystemTime@4
 NtQueryVolumeInformationFile=NtQueryVolumeInformationFile@20
 NtReadFile=NtReadFile@36
 ;NtRequestPort@8
@@ -165,6 +166,7 @@ NtSetInformationFile=NtSetInformationFile@20
 NtSetInformationProcess=NtSetInformationProcess@16
 NtSetInformationThread=NtSetInformationThread@16
 NtSetSecurityObject=NtSetSecurityObject@12
+NtSetSystemTime=NtSetSystemTime@8
 NtUnlockFile=NtUnlockFile@20
 ;NtVdmControl@8 <--- ?
 NtWaitForSingleObject=NtWaitForSingleObject@12
@@ -183,7 +185,11 @@ RtlLargeIntegerAdd
 RtlLargeIntegerGreaterThan
 RtlLargeIntegerShiftRight
 RtlMoveMemory
+RtlSecondsSince1970ToTime
+RtlSecondsSince1980ToTime
 RtlTimeFieldsToTime
+RtlTimeToSecondsSince1970
+RtlTimeToSecondsSince1980
 RtlTimeToTimeFields
 RtlZeroMemory
 ZwAccessCheckAndAuditAlarm=ZwAccessCheckAndAuditAlarm@44
@@ -239,6 +245,7 @@ ZwQuerySection=ZwQuerySection@20
 ZwQuerySecurityObject=ZwQuerySecurityObject@20
 ZwQuerySymbolicLinkObject=ZwQuerySymbolicLinkObject@12
 ZwQuerySystemInformation=ZwQuerySystemInformation@16
+ZwQuerySystemTime=ZwQuerySystemTime@4
 ZwQueryValueKey=ZwQueryValueKey@24
 ZwQueryVolumeInformationFile=ZwQueryVolumeInformationFile@20
 ZwReadFile=ZwReadFile@36
@@ -389,7 +396,7 @@ HalSetBusDataByOffset
 HalSetDisplayParameters
 ;HalSetEnvironmentVariable
 ;HalSetProfileInterval
-;HalSetRealTimeClock
+HalSetRealTimeClock
 ;HalSetTimeIncrement
 ;HalStartNextProcessor
 ;HalStartProfileInterrupt
diff --git a/reactos/ntoskrnl/rtl/time.c b/reactos/ntoskrnl/rtl/time.c
index c4b232a3ba1..2b64714347e 100644
--- a/reactos/ntoskrnl/rtl/time.c
+++ b/reactos/ntoskrnl/rtl/time.c
@@ -1,4 +1,5 @@
-/*
+/* $Id: time.c,v 1.8 1999/10/24 17:51:54 ekohl Exp $
+ *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
  * FILE:            kernel/rtl/time.c
@@ -31,6 +32,10 @@
 #define DAYSPERLEAPYEAR    366
 #define MONSPERYEAR        12
 
+#define TICKSTO1970         0x019db1ded53e8000
+#define TICKSTO1980         0x01a8e79fe1d58000
+
+
 static const int YearLengths[2] = {DAYSPERNORMALYEAR, DAYSPERLEAPYEAR};
 static const int MonthLengths[2][MONSPERYEAR] =
 {
@@ -189,3 +194,65 @@ BOOLEAN RtlTimeFieldsToTime(PTIME_FIELDS tfTimeFields,
 
   return TRUE;
 }
+
+
+VOID
+RtlSecondsSince1970ToTime (ULONG SecondsSince1970,
+                           PLARGE_INTEGER Time)
+{
+   LONGLONG llTime;
+
+   llTime = (SecondsSince1970 * TICKSPERSEC) + TICKSTO1970;
+
+   *Time = *(LARGE_INTEGER *)&llTime;
+}
+
+
+VOID
+RtlSecondsSince1980ToTime (ULONG SecondsSince1980,
+                           PLARGE_INTEGER Time)
+{
+   LONGLONG llTime;
+
+   llTime = (SecondsSince1980 * TICKSPERSEC) + TICKSTO1980;
+
+   *Time = *(LARGE_INTEGER *)&llTime;
+}
+
+
+BOOLEAN
+RtlTimeToSecondsSince1970 (PLARGE_INTEGER Time,
+                           PULONG SecondsSince1970)
+{
+   LARGE_INTEGER liTime;
+
+   liTime.QuadPart = Time->QuadPart - TICKSTO1970;
+   liTime.QuadPart = liTime.QuadPart / TICKSPERSEC;
+
+   if (liTime.u.HighPart != 0)
+      return FALSE;
+
+   *SecondsSince1970 = liTime.u.LowPart;
+
+   return TRUE;
+}
+
+
+BOOLEAN
+RtlTimeToSecondsSince1980 (PLARGE_INTEGER Time,
+                           PULONG SecondsSince1980)
+{
+   LARGE_INTEGER liTime;
+
+   liTime.QuadPart = Time->QuadPart - TICKSTO1980;
+   liTime.QuadPart = liTime.QuadPart / TICKSPERSEC;
+
+   if (liTime.u.HighPart != 0)
+      return FALSE;
+
+   *SecondsSince1980 = liTime.u.LowPart;
+
+   return TRUE;
+}
+
+/* EOF */