How do I restart countdown timer to 120 seconds every time a new user lands on the page?

I am trying to use this snippet to refresh a countdown timer to 120 seconds when a new user lands on the page. Any help is appreciated.

I am having trouble on two things: how to set the start date to the current time and then to have this countdown from 120 seconds vs. 7 days.

<style>
    #countdown {
        font-size: 36px;
        font-weight: bold;
        color: white;
        text-align: center;
        margin: 20px 0;
    }
</style>

<p id="countdown"></p>

<script>
    function updateCountdown() {
        let startTime = new Date("2023-02-28T15:22:00");
        const currentTime = new Date();
        let diffTime = startTime - currentTime;
        let totalSeconds = diffTime / 1000;

        while (totalSeconds <= 0) {
            startTime.setDate(startTime.getDate() + 7);
            diffTime = startTime - currentTime;
            totalSeconds = diffTime / 1000;
        }

        const days = Math.floor(totalSeconds / (24 * 60 * 60));
        const hours = Math.floor((totalSeconds % (24 * 60 * 60)) / (60 * 60));
        const minutes = Math.floor((totalSeconds % (60 * 60)) / 60);
        const seconds = Math.floor(totalSeconds % 60);

        document.getElementById("countdown").innerHTML = `${days}d ${hours}h ${minutes}m ${seconds}s`;
    }

    setInterval(updateCountdown, 1000);
</script>

You can use

document.addEventListener('DOMContentLoaded', function() {
   // reset timer
});

like this