Get Text from id="countdowndate" into new Date via Javascript

Question

Apologies i know this is likely to be vey simple for many but appreciate the help. Im creating a countdown based on code collected from various spots including here.

The text date in the HTML ID "countdowndate" will be updated dynamically elsewhere. What i'd like to is replace the date in var end = new Date('10/26/2023 4:00 PM'); with the date from id="countdown". Full code below and thank you.

<div class="gwd-page-content gwd-page-size">
          <!-- Display the countdown timer in an element -->
          <p id="countdown" class="gwd-p-1m9p"></p>
          <p id="countdowndate" class="gwd-p-hm4b">'10/26/2026 6:00 PM'</p>
        </div>
      </gwd-page>
    </gwd-pagedeck>
  </gwd-google-ad>
            <script>              

            var end = new Date('10/26/2023 4:00 PM');

            var _second = 1000;
            var _minute = _second * 60;
            var _hour = _minute * 60;
            var _day = _hour * 24;
            var timer;

            function showRemaining() {
              var now = new Date();
              var nowUTC = new Date(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate(), now.getUTCHours(), now.getUTCMinutes(), now.getUTCSeconds());
              var distance = end - nowUTC;
              if (distance < 0) {

                clearInterval(timer);
                document.getElementById('countdown').innerHTML = 'The Lottery Draw is Closed';

                return;
              }
              var days = Math.floor(distance / _day);
              var hours = Math.floor((distance % _day) / _hour);
              var minutes = Math.floor((distance % _hour) / _minute);
              var seconds = Math.floor((distance % _minute) / _second);

              document.getElementById('countdown').innerHTML = days + ' days ' + hours + ' hours ' + minutes + ' mins ' + seconds + ' secs';
            }

            timer = setInterval(showRemaining, 1000);
          </script>

Tried lots of things but really shooting in the dark as im no coder.