Index: sys/i386/isa/clock.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/isa/clock.c,v
retrieving revision 1.237
diff -u -r1.237 clock.c
--- sys/i386/isa/clock.c	15 Jun 2007 22:58:13 -0000	1.237
+++ sys/i386/isa/clock.c	10 Jul 2007 09:06:23 -0000
@@ -704,7 +704,12 @@
 #else
 	ct.year += 2000;
 #endif
-	clock_ct_to_ts(&ct, &ts);
+	/* Should we set dow = -1 because some clocks don't set it correctly? */
+	if (clock_ct_to_ts(&ct, &ts)) {
+		printf("Invalid time in real time clock.\n");
+		printf("Check and reset the date immediately!\n");
+		return;
+	}
 	ts.tv_sec += utc_offset();
 	tc_setclock(&ts);
 }
Index: sys/ia64/ia64/clock.c
===================================================================
RCS file: /home/ncvs/src/sys/ia64/ia64/clock.c,v
retrieving revision 1.30
diff -u -r1.30 clock.c
--- sys/ia64/ia64/clock.c	19 Oct 2006 00:53:35 -0000	1.30
+++ sys/ia64/ia64/clock.c	3 Apr 2007 09:06:42 -0000
@@ -142,7 +142,10 @@
 	ct.mon = tm.tm_mon;
 	ct.year = tm.tm_year;
 	ct.dow = -1;
-	clock_ct_to_ts(&ct, &ts);
+	if (clock_ct_to_ts(&ct, &ts)) {
+		printf("Invalid time in real time clock.\n");
+		printf("Check and reset the date immediately!\n");
+	}
 	ts.tv_sec += utc_offset();
 
 	/*
Index: sys/kern/subr_clock.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/subr_clock.c,v
retrieving revision 1.11
diff -u -r1.11 subr_clock.c
--- sys/kern/subr_clock.c	2 Oct 2006 18:23:37 -0000	1.11
+++ sys/kern/subr_clock.c	3 Apr 2007 09:00:39 -0000
@@ -151,7 +151,7 @@
 	  	days += days_in_month(year, i);
 	days += (ct->day - 1);
 
-	/* Another sanity check. */
+	/* XXX Dow sanity check. Dow is not used, so should we check it? */
 	if (ct->dow != -1 && ct->dow != day_of_week(days))
 		return (EINVAL);
 
Index: sys/pc98/cbus/clock.c
===================================================================
RCS file: /home/ncvs/src/sys/pc98/cbus/clock.c,v
retrieving revision 1.160
diff -u -r1.160 clock.c
--- sys/pc98/cbus/clock.c	4 Jun 2007 18:25:08 -0000	1.160
+++ sys/pc98/cbus/clock.c	10 Jul 2007 09:06:57 -0000
@@ -638,7 +638,12 @@
 	ct.year = bcd2bin(rtc_inb() & 0xff) + 1900;	/* year */
 	if (ct.year < 1995)
 		ct.year += 100;
-	clock_ct_to_ts(&ct, &ts);
+	/* Should we set dow = -1 because some clocks don't set it correctly? */
+	if (clock_ct_to_ts(&ct, &ts)) {
+		printf("Invalid time in real time clock.\n");
+		printf("Check and reset the date immediately!\n");
+		return;
+	}
 	ts.tv_sec += utc_offset();
 	tc_setclock(&ts);
 }
Index: sys/sparc64/sparc64/eeprom.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/sparc64/eeprom.c,v
retrieving revision 1.12
diff -u -r1.12 eeprom.c
--- sys/sparc64/sparc64/eeprom.c	16 Jun 2007 23:07:53 -0000	1.12
+++ sys/sparc64/sparc64/eeprom.c	27 Jun 2007 08:47:28 -0000
@@ -170,9 +170,11 @@
 	}
 
 	if (bootverbose) {
-		mk48txx_gettime(dev, &ts);
-		device_printf(dev, "current time: %ld.%09ld\n", (long)ts.tv_sec,
-		    ts.tv_nsec);
+		if (mk48txx_gettime(dev, &ts) != 0)
+			device_printf(dev, "invalid time");
+		else
+			device_printf(dev, "current time: %ld.%09ld\n",
+			    (long)ts.tv_sec, ts.tv_nsec);
 	}
 
 	return (0);
Index: sys/sparc64/sparc64/rtc.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/sparc64/rtc.c,v
retrieving revision 1.6
diff -u -r1.6 rtc.c
--- sys/sparc64/sparc64/rtc.c	16 Jun 2007 23:17:23 -0000	1.6
+++ sys/sparc64/sparc64/rtc.c	27 Jun 2007 08:53:16 -0000
@@ -208,9 +208,11 @@
 	}
 
 	if (bootverbose) {
-		mc146818_gettime(dev, &ts);
-		device_printf(dev, "current time: %ld.%09ld\n", (long)ts.tv_sec,
-		    ts.tv_nsec);
+		if (mc146818_gettime(dev, &ts) != 0)
+			device_printf(dev, "invalid time");
+		else
+			device_printf(dev, "current time: %ld.%09ld\n",
+			    (long)ts.tv_sec, ts.tv_nsec);
 	}
 
 	return (0);