The JavaScript Date object can be used to count down to a specified daily time. For instance, this can be used for a “daily deals” timer, where at the end of the time period the deal is no longer available and perhaps hidden.

<!-- timer will appear here -->
<h3>Only <span id="timer" style="color: red;"></span> left for today's deal!</h3>

The following would reset at midnight each day, where, at that point, the “deal” might switch to something new.

(function() {
    
    // new date (deadline)
    let start = new Date;
    start.setHours(24, 0, 0); // set deadline as midnight

    // set number of digits
    function padding(num) {
        return ('0' + parseInt(num)).substr(-2);
    }

    // counter
    function ticker() {
        // new date object (current)
        let now = new Date;

        // use today or tomorrow (useful if the deadline is not midnight)
        if (now > start) { // too late for today, go to tomorrow
            start.setDate(start.getDate() + 1);
        }

        // get time remaining
        let remaining = ((start - now) / 1000);
        let hh = padding((remaining / 60 / 60) % 60);
        let mm = padding((remaining / 60) % 60);
        let ss = padding(remaining % 60);

        // output time remaining
        document.getElementById('timer').innerHTML = hh + ':' + mm + ':' + ss;
        setTimeout(ticker, 1000);

    }

        // start after load
        document.addEventListener('DOMContentLoaded', ticker);

})();

Example:

Only 10:00:47 left for today’s deal!