diff --git a/lang/cem/libcc/gen/localtime.c b/lang/cem/libcc/gen/localtime.c
index b931ee3ff..b8e205ff4 100644
--- a/lang/cem/libcc/gen/localtime.c
+++ b/lang/cem/libcc/gen/localtime.c
@@ -25,13 +25,13 @@ localtime(clock)
 	register struct tm *gmt;
 	long cl;
 	int begindst, enddst;
-	extern int daylight;
-	extern long timezone;
+	extern int __daylight;
+	extern long __timezone;
 
 	tzset();
-	cl = *clock - timezone;
+	cl = *clock - __timezone;
 	gmt = gmtime(&cl);
-	if (daylight) {
+	if (__daylight) {
 		/* daylight saving time.
 		   Unfortunately, rules differ for different countries.
 		   Implemented here are heuristics that got it right
@@ -45,6 +45,7 @@ localtime(clock)
 		     (gmt->tm_yday==begindst && gmt->tm_hour>=2)) &&
 	    	    (gmt->tm_yday<enddst || 
 		     (gmt->tm_yday==enddst && gmt->tm_hour<3))) {
+			/* it all happens between 2 and 3 */
 			cl += 1*60*60;
 			gmt = gmtime(&cl);
 			gmt->tm_isdst++;
diff --git a/lang/cem/libcc/gen/tzset.c b/lang/cem/libcc/gen/tzset.c
index 1f7a83b8b..4c74df8fd 100644
--- a/lang/cem/libcc/gen/tzset.c
+++ b/lang/cem/libcc/gen/tzset.c
@@ -7,9 +7,15 @@
 #endif
 #endif
 
+#ifdef USG
 long	timezone = -1 * 60;
 int	daylight = 1;
 char	*tzname[] = {"MET", "MDT",};
+#endif
+
+long __timezone = -1 * 60;
+int __daylight = 1;
+char *__tzname[] = {"MET", "MDT", };
 
 tzset()
 {
@@ -18,15 +24,15 @@ tzset()
 	struct timezone tzon;
 
 	gettimeofday(&tval, &tzon);
-	timezone = tzon.tz_minuteswest * 60L;
-	daylight = tzon.tz_dsttime;
+	__timezone = tzon.tz_minuteswest * 60L;
+	__daylight = tzon.tz_dsttime;
 #else
 #ifndef USG
 	struct timeb time;
 
 	ftime(&time);
-	timezone = time.timezone*60L;
-	daylight = time.dstflag;
+	__timezone = time.timezone*60L;
+	__daylight = time.dstflag;
 #endif
 #endif
 
@@ -48,9 +54,15 @@ tzset()
 		while(*p >= '0' && *p <= '9')
 			n = 10 * n + (*p++ - '0');
 		n *= sign;
-		timezone = ((long)(n * 60)) * 60;
-		daylight = (*p != '\0');
+		__timezone = ((long)(n * 60)) * 60;
+		__daylight = (*p != '\0');
 		strncpy(tzname[1], p, 3);
 	}
 	}
+#ifdef USG
+	timezone = __timezone;
+	daylight = __daylight;
+	tzname[0] = __tzname[0];
+	tzname[1] = __tzname[1];
+#endif
 }