To convert a string in to date object Date() method should be used. This method creates a date instance that represents a single moment in time in a platform-independent format.
Example
In the following example a string named "str" is initially parsed using JSON.parse() method and then converted in to date object using Date() method.
<html>
<body>
<script>
var str = '{"name":"Ram", "DOB":"1980-11-1", "country":"India"}';
var dateObj = JSON.parse(str);
dateObj.DOB = new Date(dateObj.DOB);
document.write(dateObj.DOB);
</script>
</body>
</html>Output
Thu Nov 01 0198 00:00:00 GMT+0553 (India Standard Time)