diff --git a/sys/arch/vax/include/clock.h b/sys/arch/vax/include/clock.h
index 30152d6a5dc7..dad4111a8e30 100644
--- a/sys/arch/vax/include/clock.h
+++ b/sys/arch/vax/include/clock.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: clock.h,v 1.7 2009/12/12 14:44:09 tsutsui Exp $ */
+/*	$NetBSD: clock.h,v 1.8 2010/11/19 03:31:24 uwe Exp $ */
 /*
  * Copyright (c) 1996 Ludd, University of Lule}, Sweden.
  * All rights reserved.
@@ -37,7 +37,7 @@
 /*
  * Time constants. These are unlikely to change.
  */
-#define IS_LEAPYEAR(y) (((y % 4) == 0) && (y % 100))
+#define IS_LEAPYEAR(y) ((((y % 4) == 0) && ((y % 100) != 0)) || ((y % 400) == 0))
 
 #define SEC_PER_MIN	(60)
 #define SEC_PER_HOUR	(SEC_PER_MIN * 60)
diff --git a/sys/arch/vax/vax/clock.c b/sys/arch/vax/vax/clock.c
index 84ce4568bf43..83641ee4d74d 100644
--- a/sys/arch/vax/vax/clock.c
+++ b/sys/arch/vax/vax/clock.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: clock.c,v 1.53 2010/07/01 19:50:12 ragge Exp $	 */
+/*	$NetBSD: clock.c,v 1.54 2010/11/19 03:31:24 uwe Exp $	 */
 /*
  * Copyright (c) 1995 Ludd, University of Lule}, Sweden.
  * All rights reserved.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.53 2010/07/01 19:50:12 ragge Exp $");
+__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.54 2010/11/19 03:31:24 uwe Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -199,18 +199,18 @@ yeartonum(int y)
 {
 	int n;
 
-	for (n = 0, y -= 1; y > 69; y--)
+	for (n = 0, y -= 1; y > 1969; y--)
 		n += SECPERYEAR(y);
 	return n;
 }
 
 /* 
- * Converts tick number to a year 70 ->
+ * Converts tick number to a year 1970 ->
  */
 int
 numtoyear(int num)
 {
-	int y = 70, j;
+	int y = 1970, j;
 	while(num >= (j = SECPERYEAR(y))) {
 		y++;
 		num -= j;