Index: generic/tcl.h
==================================================================
--- generic/tcl.h
+++ generic/tcl.h
@@ -412,11 +412,11 @@
 #endif /* TCL_WIDE_INT_IS_LONG */
 
 #if defined(__WIN32__)
 #   ifdef __BORLANDC__
 	typedef struct stati64 Tcl_StatBuf;
-#   elif defined(_WIN64) || defined(__MINGW_USE_VC2005_COMPAT) || defined(_USE_64BIT_TIME_T)
+#   elif defined(_WIN64)  || defined(_USE_64BIT_TIME_T)
 	typedef struct __stat64 Tcl_StatBuf;
 #   elif (defined(_MSC_VER) && (_MSC_VER < 1400)) || defined(_USE_32BIT_TIME_T)
 	typedef struct _stati64	Tcl_StatBuf;
 #   else
 	typedef struct _stat32i64 Tcl_StatBuf;

Index: generic/tclBasic.c
==================================================================
--- generic/tclBasic.c
+++ generic/tclBasic.c
@@ -411,23 +411,17 @@
     if (sizeof(Tcl_CallFrame) < sizeof(CallFrame)) {
 	/*NOTREACHED*/
 	Tcl_Panic("Tcl_CallFrame must not be smaller than CallFrame");
     }
 
-#if defined(_WIN32) && !defined(_WIN64) && !defined(_USE_64BIT_TIME_T) \
-	    && !defined(__MINGW_USE_VC2005_COMPAT)
-    /* If Tcl is compiled on Win32 using -D_USE_64BIT_TIME_T or
-     * -D__MINGW_USE_VC2005_COMPAT, the result is a binary incompatible
-     * with the 'standard' build of Tcl: All extensions using Tcl_StatBuf
-     * or interal functions like TclpGetDate() need to be recompiled in
+#if defined(_WIN32) && !defined(_WIN64) && !defined(_USE_64BIT_TIME_T)
+    /* If Tcl is compiled on Win32 using -D_USE_64BIT_TIME_T
+     * the result is a binary incompatible with the 'standard' build of
+     * Tcl: All extensions using Tcl_StatBuf need to be recompiled in
      * the same way. Therefore, this is not officially supported.
      * In stead, it is recommended to use Win64 or Tcl 9.0 (not released yet)
      */
-    if (sizeof(time_t) != 4) {
-	/*NOTREACHED*/
-	Tcl_Panic("<time.h> is not compatible with MSVC");
-    }
     if ((TclOffset(Tcl_StatBuf,st_atime) != 32)
 	    || (TclOffset(Tcl_StatBuf,st_ctime) != 40)) {
 	/*NOTREACHED*/
 	Tcl_Panic("<sys/stat.h> is not compatible with MSVC");
     }

Index: win/tclWinPort.h
==================================================================
--- win/tclWinPort.h
+++ win/tclWinPort.h
@@ -12,17 +12,13 @@
  */
 
 #ifndef _TCLWINPORT
 #define _TCLWINPORT
 
-/* define _USE_64BIT_TIME_T (or make/configure option time64bit) to force 64-bit time_t */
-#if defined(_USE_64BIT_TIME_T)
-#define __MINGW_USE_VC2005_COMPAT
-#endif
 #if !defined(_WIN64) && !defined(__MINGW_USE_VC2005_COMPAT)
 /* See [Bug 3354324]: file mtime sets wrong time */
-#   define _USE_32BIT_TIME_T
+#   define __MINGW_USE_VC2005_COMPAT
 #endif
 
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #undef WIN32_LEAN_AND_MEAN

Index: win/tclWinTime.c
==================================================================
--- win/tclWinTime.c
+++ win/tclWinTime.c
@@ -843,10 +843,15 @@
     CONST time_t *t,
     int useGMT)
 {
     struct tm *tmPtr;
     time_t time;
+#if defined(_WIN64) || (defined(_USE_64BIT_TIME_T) || (defined(_MSC_VER) && _MSC_VER < 1400))
+#   define  t2 *t /* no need to cripple time to 32-bit */
+#else
+    time_t t2 = *(__time32_t *)t;
+#endif
 
     if (!useGMT) {
 #if defined(_MSC_VER) && (_MSC_VER >= 1900)
 #	undef timezone /* prevent conflict with timezone() function */
 	long timezone = 0;
@@ -875,30 +880,30 @@
 #define LOCALTIME_VALIDITY_BOUNDARY	SECSPERDAY
 #else
 #define LOCALTIME_VALIDITY_BOUNDARY	0
 #endif
 
-	if (*t >= LOCALTIME_VALIDITY_BOUNDARY) {
-	    return TclpLocaltime(t);
+	if (t2 >= LOCALTIME_VALIDITY_BOUNDARY) {
+	    return TclpLocaltime(&t2);
 	}
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1900)
 	_get_timezone(&timezone);
 #endif
 
-	time = *t - timezone;
+	time = t2 - timezone;
 
 	/*
 	 * If we aren't near to overflowing the long, just add the bias and
 	 * use the normal calculation. Otherwise we will need to adjust the
 	 * result at the end.
 	 */
 
-	if (*t < (LONG_MAX - 2*SECSPERDAY) && *t > (LONG_MIN + 2*SECSPERDAY)) {
+	if (t2 < (LONG_MAX - 2*SECSPERDAY) && t2 > (LONG_MIN + 2*SECSPERDAY)) {
 	    tmPtr = ComputeGMT(&time);
 	} else {
-	    tmPtr = ComputeGMT(t);
+	    tmPtr = ComputeGMT(&t2);
 
 	    tzset();
 
 	    /*
 	     * Add the bias directly to the tm structure to avoid overflow.
@@ -930,11 +935,11 @@
 	    tmPtr->tm_mday += (int)time;
 	    tmPtr->tm_yday += (int)time;
 	    tmPtr->tm_wday = (tmPtr->tm_wday + (int)time) % 7;
 	}
     } else {
-	tmPtr = ComputeGMT(t);
+	tmPtr = ComputeGMT(&t2);
     }
     return tmPtr;
 }
 
 /*
@@ -1464,11 +1469,15 @@
      * The MS implementation of gmtime is thread safe because it returns the
      * time in a block of thread-local storage, and Windows does not provide a
      * Posix gmtime_r function.
      */
 
+#if defined(_WIN64) || defined(_USE_64BIT_TIME_T) || (defined(_MSC_VER) && _MSC_VER < 1400)
     return gmtime(timePtr);
+#else
+    return _gmtime32((CONST __time32_t *)timePtr);
+#endif
 }
 
 /*
  *----------------------------------------------------------------------
  *
@@ -1496,11 +1505,15 @@
      * The MS implementation of localtime is thread safe because it returns
      * the time in a block of thread-local storage, and Windows does not
      * provide a Posix localtime_r function.
      */
 
+#if defined(_WIN64) || defined(_USE_64BIT_TIME_T) || (defined(_MSC_VER) && _MSC_VER < 1400)
     return localtime(timePtr);
+#else
+    return _localtime32((CONST __time32_t *)timePtr);
+#endif
 }
 
 /*
  *----------------------------------------------------------------------
  *