--- /dev/null
+var DateProto = Date.prototype
+ , INVALID_DATE = 'Invalid Date'
+ , TO_STRING = 'toString'
+ , $toString = DateProto[TO_STRING]
+ , getTime = DateProto.getTime;
+if(new Date(NaN) + '' != INVALID_DATE){
+ require('./_redefine')(DateProto, TO_STRING, function toString(){
+ var value = getTime.call(this);
+ return value === value ? $toString.call(this) : INVALID_DATE;
+ });
+}
\ No newline at end of file