var deadline = new Date("Apr 12, 2020 00:00:00").getTime();
var x = setInterval(function() {
var now = new Date().getTime();
var t = deadline - now;
var days = Math.floor(t / (1000 * 60 * 60 * 24));
var hours = Math.floor((t%(1000 * 60 * 60 * 24))/(1000 * 60 * 60));
var minutes = Math.floor((t % (1000 * 60 * 60)) / (1000 * 60));
var seconds = Math.floor((t % (1000 * 60)) / 1000);
document.getElementById("wielkanoc").innerHTML = days + "dni "
+ hours + "godzin " + minutes + "minut " + seconds + "sekund ";
    if (t < 0) {
        clearInterval(x);
        document.getElementById("wielkanoc").innerHTML = "EXPIRED";
    }
}, 1000);