How do i calculate the time remaining between the current time and a set time in javascript

I want to create a prayer app where it tells you how much time is left between current time and the time of the prayer

I tried to find the difference directly by doing this

let left = new Date(currprayer.getTime() - time.getTime() );
            document.getElementById('nextmin').innerHTML = left.getMinutes()
            document.getElementById('nexthrs').innerHTML = left.getHours()
            document.getElementById('nextsec').innerHTML = left.getSeconds()

HTML:

 <div class="details">
                <div class="next-prayer">
                    <span id="nexthrs">00</span>
                    <span>:</span>
                    <span id="nextmin">00</span>
                    <span>:</span>
                    <span id="nextsec">00</span>
                </div>
            </div>

but it keeps getting stuck on 00:00:00