diff --git a/lib/timeline/TimeStep.js b/lib/timeline/TimeStep.js
index 95a5b5e2..1d0afd12 100644
--- a/lib/timeline/TimeStep.js
+++ b/lib/timeline/TimeStep.js
@@ -93,9 +93,9 @@ TimeStep.prototype.setMoment = function (moment) {
   this.moment = moment;
 
   // update the date properties, can have a new utcOffset
-  this.current = this.moment(this.current);
-  this._start = this.moment(this._start);
-  this._end = this.moment(this._end);
+  this.current = this.moment(this.current.valueOf());
+  this._start = this.moment(this._start.valueOf());
+  this._end = this.moment(this._end.valueOf());
 };
 
 /**