diff --git a/test/schemas/date_0.xml b/test/schemas/date_0.xml
index 6c677edb..53128a91 100644
--- a/test/schemas/date_0.xml
+++ b/test/schemas/date_0.xml
@@ -13,6 +13,7 @@
   <dt1>2000-05-18T00:00:00</dt1>
   <dt2>2002-05-19T21:30:00.99</dt2>
   <dt1>1969-12-31T23:00:01-01:00</dt1>
+  <dt1>2000-06-06T00:00:00+14:00</dt1>
   <hol>--01-01</hol>
   <hol>--07-04</hol>
   <hol>--12-25</hol>
diff --git a/xmlschemastypes.c b/xmlschemastypes.c
index 1450781f..e49ef61a 100755
--- a/xmlschemastypes.c
+++ b/xmlschemastypes.c
@@ -1129,7 +1129,7 @@ xmlSchemaGetBuiltInListSimpleTypeItemType(xmlSchemaTypePtr type)
 #define VALID_HOUR(hr)          ((hr >= 0) && (hr <= 23))
 #define VALID_MIN(min)          ((min >= 0) && (min <= 59))
 #define VALID_SEC(sec)          ((sec >= 0) && (sec < 60))
-#define VALID_TZO(tzo)          ((tzo > -840) && (tzo < 840))
+#define VALID_TZO(tzo)          ((tzo >= -840) && (tzo <= 840))
 #define IS_LEAP(y)						\
 	(((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0))