JS Countdown timer

countdown.js

var target = document.getElementById('target');
var current = document.getElementById('current');

var d = new Date();
current.innerHTML = "Now: " + d;
var opening = new Date(d.getFullYear(), d.getMonth(), d.getDate(), '16', '00', '00');
var closing = new Date(d.getFullYear(), d.getMonth(), d.getDate(), '22', '00', '00');
target.innerHTML = "Open: " + opening;

var el = document.getElementById('result');
var cdown;
var result = '';
function showTime() {
    d = new Date();
    if( (d > opening) && (d < closing)) {
        cdown = new Date(closing - d);
        result = 'Lines will close in ' + ('0'+cdown.getHours()).slice(-2) + ':' + ('0'+cdown.getMinutes()).slice(-2) + ':' + ('0'+cdown.getSeconds()).slice(-2);
    } else {
        cdown = new Date(opening - d);
        result = 'Lines will open in ' + ('0'+cdown.getHours()).slice(-2) + ':' + ('0'+cdown.getMinutes()).slice(-2) + ':' + ('0'+cdown.getSeconds()).slice(-2);
    }
    el.innerHTML = result;
}

window.setInterval(showTime, 1000);