function ntos(n,l){
    n = n.toString();
    while (n.length < l){
        n = "0" + n;
    }
    return n;
}

function timespan(value){
    var days, hours, minutes, seconds;
    value = parseInt(value);

    days = parseInt(value / 86400);
    value %= 86400;
    hours = parseInt(value / 3600);
    value %= 3600;
    minutes = parseInt(value / 60);
    value %= 60;
    seconds = parseInt(value);

    var r = "";
    if (days > 0)
        r += `${days}d `;
    r += `${ntos(hours,2)}:${ntos(minutes,2)}:${ntos(seconds,2)}`;

    return r;
}