html - Changing list of time zone offset numbers to current times with JavaScript

Question

I am displaying a list of names and their time zone offset numbers in a table. The offset numbers are their time zone's offset from UTC. I need to change all of the offset numbers to show the current time in the person's time zone using JavaScript or jQuery.

What I would like to happen is the offset numbers would be replaced with the current date/time from the calcTime function... any idea what I'm doing wrong?

Here's my code:

<div class="name">John Doe</div><div class="timezone">-5</div>
<div class="name">Jane Doe</div><div class="timezone">3</div>
<div class="name">Jim Smith</div><div class="timezone">7</div>
<div class="name">Cathy Jones</div><div class="timezone">-3</div>

<script>
$(document).ready(function() {
    setTimeout(() => {
        function calcTime(offset) {
            // create Date object for current location
            d = new Date();
            // convert to msec
            // add local time zone offset
            // get UTC time in msec
            utc = d.getTime() + (d.getTimezoneOffset() * 60000);
            // create new Date object for different city
            // using supplied offset
            nd = new Date(utc + (3600000*offset));
            // return time as a string
            return "The local time is " + nd.toLocaleString();
        }

        $(".timezone").each(function(){
            h = $(this).find(".timezone").text();
            element.innerHTML = calcTime(h); 
        //alert(calcTime('-5'));
        });
    }, 1000);
});
</script>

Answer 1

I think this is what you are attempting to achieve (with significant changes).

Note the use of setInterval() rather than set time out and the structural changes to the HTML.

const utc = document.querySelector('.utc');
const collection = document.querySelectorAll('.timezone');
const outputs = document.querySelectorAll('.output');
const localeTZoffSet = new Date().getTimezoneOffset()/60 * 3600000;

setInterval(() => {
  utc.textContent = calcTime(0);
  collection.forEach((element, idx) => {
    outputs[idx].textContent = calcTime(element.textContent);
  });
});

function calcTime(offset) {
  return "The local time is " + new Date(Date.now() + localeTZoffSet + (3600000 * offset)).toLocaleTimeString();
}

<div>UTC: <span class="utc"></span></div>
<div class="name">John Doe - <span class="output"></span></div>
<div class="timezone">-5</div>
<div class="name">Jane Doe - <span class="output"></span></div>
<div class="timezone">3</div>
<div class="name">Jim Smith - <span class="output"></span></div>
<div class="timezone">7</div>
<div class="name">Cathy Jones - <span class="output"></span></div>
<div class="timezone">-3</div>