var date = \"2012-01-18T16:03\";
var date = new Date(date);
console.log(date.getMinutes());
console.log(date.getMinutes().length)
This returns 3.
If you're using AngularJS in your project, just inject $filter and use it like here:
$filter('date')(value, 'HH:mm')
You can also format the output in the template, more on filters here.
var date = new Date("2012-01-18T16:03");
console.log( (date.getMinutes()<10?'0':'') + date.getMinutes() );
Another option:
var dateTime = new Date();
var minutesTwoDigitsWithLeadingZero = ("0" + dateTime.getMinutes()).substr(-2);