Although it doesn't pad to two characters in some of the cases, it does what I expect you want

function getFormattedDate() {

    var date = new Date();

    var str = date.getFullYear() + - + (date.getMonth() + 1) + - + date.getDate() +   +  date.getHours() + : + date.getMinutes() + : + date.getSeconds();



    return str;

}