W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<body>

<h1>My First Web Page</h1>

<p>The weekend is only <span id="weekend_coundown"></span> from now!</p>

var currentHour = now.getHours();
    var hoursToSaturday = 0;

// If it's not Saturday or if it's Saturday but before 12:00 (noon),
    // consider the remaining hours to Saturday noon
    if (daysToSaturday > 0 || (daysToSaturday === 0 && currentHour < 12)) {
        hoursToSaturday = (24 - currentHour + 12) % 24;
    }

var days = daysToSaturday > 0 ? daysToSaturday + " day(s), " : "";
    var hours = hoursToSaturday > 0 ? hoursToSaturday + " hour(s)" : "";
    
    // if it's Saturday and past 12:00 (noon), the countdown should return 0.
    if (daysToSaturday === 0 && currentHour >= 12) {
        days = "";
        hours = "0 hours";
    }
    
    document.getElementById('weekend_coundown').innerText = days + hours;
}

countdownToSaturday();
setInterval(countdownToSaturday, 1000 * 60 * 60); // update the countdown every hour
</script>

</body>
</html>