function getDaysBeforeNextXmas() {
var oneMinute = 60 * 1000;
var oneHour = oneMinute * 60;
var oneDay = oneHour * 24;
var today = new Date();
var nextXmas = new Date();
nextXmas.setMonth(11);
nextXmas.setDate(25);
if (today.getMonth() == 11 && today.getDate() > 25) {
nextXmas.setFullYear(nextXmas.getFullYear() + 1);
}
var diff = nextXmas.getTime() - today.getTime();
diff = Math.floor(diff/oneDay);
return diff;
}
...
Only
document.write(getDaysBeforeNextXmas())
shopping days until Christmas.