[Seva1986]

progns,

такой пойдёт?

function getDaysLeft() {
    var daysLeft = (new Date(2012, 01, 09) - new Date())/1000/60/60/24;
    daysLeft = daysLeft>0 && daysLeft<1 ? 1 : daysLeft;
    if (daysLeft < 0) {
        clearInterval(timer);
        alert('Time is up!');
        return;
    }
    alert(daysLeft);
}

var timer = setInterval(getDaysLeft, 1000*60);
getDaysLeft();