--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/objects/NativeDate.java	Fri Feb 27 14:33:47 2015 +0100
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/objects/NativeDate.java	Mon Mar 02 14:33:55 2015 +0100
@@ -30,6 +30,7 @@
 import static java.lang.Double.isNaN;
 import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError;
 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
+
 import java.util.Locale;
 import java.util.TimeZone;
 import java.util.concurrent.Callable;
@@ -40,7 +41,6 @@
 import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
 import jdk.nashorn.internal.objects.annotations.Where;
 import jdk.nashorn.internal.parser.DateParser;
-import jdk.nashorn.internal.runtime.ConsString;
 import jdk.nashorn.internal.runtime.JSType;
 import jdk.nashorn.internal.runtime.PropertyMap;
 import jdk.nashorn.internal.runtime.ScriptEnvironment;
@@ -183,7 +183,7 @@
         case 1:
             double num;
             final Object arg = JSType.toPrimitive(args[0]);
-            if (arg instanceof String || arg instanceof ConsString) {
+            if (JSType.isString(arg)) {
                 num = parseDateString(arg.toString());
             } else {
                 num = timeClip(JSType.toNumber(args[0]));