To specify a different date, edit the script.js file.
countdown.start({
datestring : '12/31/2014'
});
Add your custom background image and overlay color at the end of the style.css file.
/* ========================================================================== */
/* ADD YOUR CUSTOMIZATIONS
/* ========================================================================== */
body{
background-image: url(../img/san-francisco.jpg);
}
.overlay{
background: rgba(50, 58, 69, 0.85);
}
That's it.