--- a/nsprpub/pr/src/misc/prtime.c
+++ b/nsprpub/pr/src/misc/prtime.c
@@ -601,16 +601,19 @@ PR_LocalTimeParameters(const PRExplodedT
      * Caveat: the validity of this calculation depends on two
      * assumptions:
      * 1. Daylight saving time was not in effect on Jan. 2, 1970.
      * 2. The time zone of the geographic location has not changed
      *    since Jan. 2, 1970.
      */
 
     secs = 86400L;
+
+    memset(&localTime, 0, sizeof(struct tm));
+
     (void) MT_safe_localtime(&secs, &localTime);
 
     /* GMT is 00:00:00, 2nd of Jan. */
 
     offset2Jan1970 = (PRInt32)localTime.tm_sec 
             + 60L * (PRInt32)localTime.tm_min
             + 3600L * (PRInt32)localTime.tm_hour
             + 86400L * (PRInt32)((PRInt32)localTime.tm_mday - 2L);