document.getElementById('id_goes_here').style.display = 'none';

Click link below
WPBeginner

print();

let timer = setInterval(function() {

  // The dispatch date is just the variable name. You can change it wo whatever. As long as you change it where ever else it is been used as well.  
  // the format for dispatch_date is ('2018-10-17 17:00:00') which is been pull from an input field with the id of "countdown_timer"
  const dispatch_date = new Date(document.getElementById("countdown_timer").value);
  const today = new Date();
  
  // console.log("dispatch_date : "+dispatch_date);
  // console.log("today : "+today);

  // get the difference
  const diff = dispatch_date - today;

  // math
  let days = Math.floor(diff / (1000 * 60 * 60 * 24));
  let hours = Math.floor((diff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  let minutes = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
  let seconds = Math.floor((diff % (1000 * 60)) / 1000);

  // display
  document.getElementById("timer").innerHTML =

  //Days - Hours - Minutes - Seconds
    "</div class='timer-p'>This Stock list Expires in </div> \ <div class=\"days\"> \
  <div class=\"numbers\">" + days + "</div>Days</div> \
<div class=\"hours\"> \
  <div class=\"numbers\">" + hours + "</div>Hours</div> \
<div class=\"minutes\"> \
  <div class=\"numbers\">" + minutes + "</div>Minutes</div> \
<div class=\"seconds\"> \
  <div class=\"numbers\">" + seconds + "</div>Seconds</div> \
</div>";

}, 1000);

Here’s the Stackoverflow link

Here’s the improved answer

//The Function
    function in_array_r($needle, $haystack, $strict = false) {
        foreach ($haystack as $item) {
            if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) {
                return true;
                $found = 'yes';
            }
        }
        $found = 'no';
        return false;
    }

//The Function in use
        //Set the result as a var so you can check it.
  $found = in_array_r($search_pre_order_date,$dates_array) ? 'found' : 'not found';
  
        //If the result is equal to something do something...
        if ($found == 'found') {
    echo 'Yes this item is in the array';
  }elseif ($found == 'not found') {
                echo 'Nope not in the array';
  }