[рони]

bridun,

<div id="conf_time"></div>
 <script>
var countDownDate = new Date("02/18/2019 23:01:00 GMT+0300").getTime();
function two(num)
{
    return (num <= 9 ? "0" : "")+ num

}
var x = setInterval(function() {

    var now = new Date().getTime();

    var distance = countDownDate - now;

    var days = Math.floor(distance / (1000 * 60 * 60 * 24));
    var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
    var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
    var seconds = Math.floor((distance % (1000 * 60)) / 1000);

    document.getElementById("conf_time").innerHTML = "начало через : " + two(hours) + ":" + two(minutes) + ":" + two(seconds);

    if (distance < 0) {
        clearInterval(x);
        document.getElementById("conf_time").innerHTML = "мероприятие уже проходит";
    }
}, 1000);

  </script>