How to convert date into jason

Question

my code is that how to convert date into jason format

<script>

$(document).ready(function () {

$.getJSON("@Url.Action("index1", "employ")",

function (json)

{

var tr;

//Append each row to html table

for (var i = 0; i < json.length; i++) {

tr = $('<tr/>');

tr.append("<td>" + json[i].emp_id + "</td>");

tr.append("<td>" + json[i].emp_name + "</td>");

tr.append("<td>" + json[i].gender + "</td>");

tr.append("<td>" + json[i].join_date+ "</td>");

tr.append("<td>"+ +" </td>");

$('table').append(tr);

}

});

});

</script>