Update date.js

src/js/validator/date.js

@@ -89,7 +89,7 @@
                 month = date[$.inArray('MM', dateFormat)],
                 day   = date[$.inArray('DD', dateFormat)];
 
-            if (!year || !month || !day) {
+            if (!year || !month || !day || year.length !== 4) {
                 return {
                     valid: false,
                     message: options.message || $.fn.bootstrapValidator.i18n.date['default']