// Set the date we're counting down to
var countDownDate = new Date("Mar 11, 2019 09:00:00").getTime();

// Update the count down every 1 second
var x = setInterval(function () {

    // Get todays date and time
    var now = new Date().getTime();

    // Find the distance between now and the count down date
    var distance = countDownDate - now;

    // Time calculations for days, hours, minutes and seconds
    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);

    // Output the result in an element with id="demo"
    document.getElementById("days").innerHTML = days;
    document.getElementById("hours").innerHTML = hours;
    document.getElementById("minutes").innerHTML = minutes;
    document.getElementById("seconds").innerHTML = seconds;


    // If the count down is over, write some text 
    if (distance < 0) {
        clearInterval(x);
        document.getElementById("timer").style.visibility = "none";
    }
}, 1000);
// Set the date we're counting down to
var countDownDate = new Date("Mar 11, 2019 14:00:00").getTime();

// Update the count down every 1 second
var x = setInterval(function () {

    // Get todays date and time
    var now = new Date().getTime();

    // Find the distance between now and the count down date
    var distance = countDownDate - now;

    // If the count down is over, write some text 
    if (distance < 0) {
        clearInterval(x);
        document.getElementById("timer").style.visibility = "hidden";
        return;
    }
    
    // Time calculations for days, hours, minutes and seconds
    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);

    // Output the result in an element with id="demo"
    document.getElementById("days").innerHTML = days;
    document.getElementById("hours").innerHTML = hours;
    document.getElementById("minutes").innerHTML = minutes;
    document.getElementById("seconds").innerHTML = seconds;

}, 1000);
Fix to hide countdown when it reaches 0