toHHMM = (secs) => {
        var hours = Math.floor(secs / 3600) < 10 ? ("00" + Math.floor(secs / 3600)).slice(-2) : Math.floor(secs / 3600);
        var minutes = ("00" + Math.floor((secs % 3600) / 60)).slice(-2);
        return hours + ":" + minutes;
    }