diff --git a/lib/timeline/component/TimeAxis.js b/lib/timeline/component/TimeAxis.js
index 88d775f6db..de47fee353 100644
--- a/lib/timeline/component/TimeAxis.js
+++ b/lib/timeline/component/TimeAxis.js
@@ -45,7 +45,7 @@ class TimeAxis extends Component {
       showMajorLabels: true,
       showWeekScale: false,
       maxMinorChars: 7,
-      format: TimeStep.FORMAT,
+      format: util.extend({}, TimeStep.FORMAT),
       moment,
       timeAxis: null
     };