Extjs: Creating a date object from a AJAX (M$) formatted string?

I have an ExtJS listview with a JsonStore connected to a .NET webservice. One of my columns has the type Date which I want to populate from a .NET DateTime object.

{
    header: 'Date',                
    dateFormat: 'M$',
    type: 'date',
    tpl: '{myTime:date("j. M Y, G:i")}',开发者_StackOverflow中文版
    dataIndex: 'myTime'
}

My result from the webservice is

/Date(1313669548625)/

I am getting an Invalid date error and a quick test concurs:

var myTime = '/Date(1313669548625)/';
var dt = new Date(myTime);

How can I serve/parse the DateTime object so that my listview can handle the result?

I have interpreted the ExtJS documentation as ExtJS has extended the builtin Date object with parsing of MS Ajax formatted DateTime objects (M$).

I checked and the way to use it is var dt = new Date(Date(1313669548625)) without the slashes and quotes