solved bugs for same date instance

js/bootstrap-datetimepicker.js

@@ -1192,9 +1192,9 @@
 
     _setDate: function (date, which) {
       if (!which || which === 'date')
-        this.date = date;
+        this.date = new Date(date);
       if (!which || which === 'view')
-        this.viewDate = date;
+        this.viewDate = new Date(date);
       this.fill();
       this.setValue();
       var element;