A function that converts an integer (seconds) to a DHHMMSS string.

intToDHHMMSS.js

String.prototype.toDHHMMSS = function () {
    var sec_num = parseInt(this, 10); 
    var days    = Math.floor(sec_num / 86400)
    var hours   = Math.floor((sec_num - (days * 86400)) / 3600);
    var minutes = Math.floor(((sec_num - (days * 86400)) - (hours * 3600)) / 60);
    var seconds = sec_num - (days * 86400) - (hours * 3600) - (minutes * 60);

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    return days + "d " + hours+'h '+minutes+'m '+seconds+"s";
}