JavaScript date format from UNIX timestamp

timestamp.js

function date_str_from_unix(unix_timestamp) {
    // var my_date_str = date_str_from_unix(1370383708);
    // my_date_str returns "2013-06-04 17:08"
    var leading_zero = function(i) {
      return i.toString().length < 2 ? "0" + i : i
    }
    var date = new Date(unix_timestamp * 1000);
    var date_str = date.getFullYear() + "-" + leading_zero(date.getMonth() + 1)
                 + "-" + leading_zero(date.getDate()) + " "
                 + leading_zero(date.getHours()) + ":"
                 + leading_zero(date.getMinutes());
    return date_str;
}