diff --git a/src/mzscheme/src/file.c b/src/mzscheme/src/file.c
index eadf6453c4..4b745eae6b 100644
--- a/src/mzscheme/src/file.c
+++ b/src/mzscheme/src/file.c
@@ -2035,24 +2035,72 @@ char *scheme_expand_string_filename(Scheme_Object *o, const char *errorin, int *
 # define GET_FF_NAME(fd) fd.cFileName
 static time_t convert_date(const FILETIME *ft)
 {
-  LONGLONG l;
+  LONGLONG l, delta;
   FILETIME ft2;
-  SYSTEMTIME st, st2;
+  SYSTEMTIME st;
+  TIME_ZONE_INFORMATION tz;
 
-  /* FindFirstFile incorrectly shifts for daylight saving.  Counteract
-     the difference by using FileTimeToLocalFileTime, which also
-     shifts incorrectly. There's a race condition here, because we
-     might cross the daylight-saving boundary between the time that
-     FindFirstFile runs and FileTimeToLocalFileTime runs. Cross your
-     fingers... */
+  /* FindFirstFile incorrectly shifts for daylight saving. It
+     subtracts an hour to get to UTC when daylight saving is in effect
+     now, even when daylight saving was not in effect when the file
+     was saved.  Counteract the difference. There's a race condition
+     here, because we might cross the daylight-saving boundary between
+     the time that FindFirstFile runs and GetTimeZoneInformation
+     runs. Cross your fingers... */
   FileTimeToLocalFileTime(ft, &ft2);
   FileTimeToSystemTime(&ft2, &st);
-  TzSpecificLocalTimeToSystemTime(NULL, &st, &st2);
-  SystemTimeToFileTime(&st2, &ft2);
+  
+  delta = 0;
+  if (GetTimeZoneInformation(&tz) == TIME_ZONE_ID_DAYLIGHT) {
+    /* Daylight saving is in effect now, so there may be a bad
+       shift. Check the file's date. */
+    int start_day_of_month, end_day_of_month, first_day_of_week, diff, end_shift;
 
-  l = ((((LONGLONG)ft2.dwHighDateTime << 32) | ft2.dwLowDateTime)
+    /* Valid only when the months match: */
+    first_day_of_week = (st.wDayOfWeek - (st.wDay - 1 - (((st.wDay - 1) / 7) * 7)));
+    if (first_day_of_week < 0)
+      first_day_of_week += 7;
+
+    diff = (tz.DaylightDate.wDayOfWeek - first_day_of_week);
+    if (diff < 0)
+      diff += 7;
+    start_day_of_month = 1 + (((tz.DaylightDate.wDay - 1) * 7)
+			      + diff);
+	
+    diff = (tz.StandardDate.wDayOfWeek - first_day_of_week);
+    if (diff < 0)
+      diff += 7;
+    end_day_of_month = 1 + (((tz.StandardDate.wDay - 1) * 7)
+			    + diff);
+
+    /* Count ambigious range (when the clock goes back) as
+       in standard time. We assume that subtracting the 
+       ambiguous range does not go back into the previous day,
+       and that the shift is a multiple of an hour. */
+    end_shift = ((tz.StandardBias - tz.DaylightBias) / 60);
+
+    if ((st.wMonth < tz.DaylightDate.wMonth)
+	|| ((st.wMonth == tz.DaylightDate.wMonth)
+	    && ((st.wDay < start_day_of_month)
+		|| ((st.wDay == start_day_of_month)
+		    && (st.wHour < tz.DaylightDate.wHour))))) {
+      /* Daylight saving had not yet started. */
+      delta = ((tz.StandardBias - tz.DaylightBias) * 60);
+    } else if ((st.wMonth > tz.StandardDate.wMonth)
+	       || ((st.wMonth == tz.StandardDate.wMonth)
+		   && ((st.wDay > end_day_of_month)
+		       || ((st.wDay == end_day_of_month)
+			   && (st.wHour >= (tz.StandardDate.wHour
+					    - end_shift)))))) {
+      /* Daylight saving was already over. */
+      delta = ((tz.StandardBias - tz.DaylightBias) * 60);
+    }
+  }
+
+  l = ((((LONGLONG)ft->dwHighDateTime << 32) | ft->dwLowDateTime)
        - (((LONGLONG)0x019DB1DE << 32) | 0xD53E8000));
   l /= 10000000;
+  l += delta;
 
   return (time_t)l;
 }