When an ASP.NET MVC 4 action returns JSON containing a DateTime value, the value is serialized into a format that cannot be natively understood by JavaScript. Here is some code to process the value into a JavaScript Date. A better solution than this is to use JSON.NET to serialize dates instead. See https://gist.github.com/danielgreen/5669903

Readme.md

https://gist.github.com/danielgreen/5669903

http://www.hanselman.com/blog/OnTheNightmareThatIsJSONDatesPlusJSONNETAndASPNETWebAPI.aspx

http://www.dalsoft.co.uk/blog/index.php/2012/01/10/asp-net-mvc-3-improved-jsonvalueproviderfactory-using-json-net

https://gist.github.com/DalSoft/1588818

http://stackoverflow.com/questions/11490506/mvc3-controller-with-specific-jsonconverter

ParseJSONDates.js

function dateTimeReviver (key, value) {
  var a;
  if (typeof value === 'string') {
      a = /\/Date\((\d*)\)\//.exec(value);
      if (a) {
          return new Date(+a[1]);
      }
  }
  return value;
}

$.ajax({
  type: "GET",
  cache: false,
  url: "http://example.com/GetADate,
  success: function (data) {
    var parsedDate = JSON.parse(JSON.stringify(data.ExampleDate), dateTimeReviver);
    alert(parsedDate); // Now we have a proper Date object
  }
});