Thank you for the support.
In fact I found a trick, I add a virtual point in the dataPoints in a past time which has nothing related to my chart. Like that it works as I want. http://jsfiddle.net/x1tr0kkv/1/
Thank you for the answer, but unfortunately it is not my issue…
Please have a look on this: http://jsfiddle.net/wkgqsw8c/