private String timeToString(long seconds) {
        long minutes = seconds / 60;
        seconds = seconds - minutes*60;

        if (minutes == 0 && seconds == 0)
            return "zero seconds";
        else if (minutes == 0)
            return secondsToString(seconds);
        else if (seconds == 0)
            return minutesToString(minutes);
        else
            return minutesToString(minutes) + " and " + secondsToString(seconds);
    }