How to create event time(Timmer) in PHP and Javascript?

Create event time(Timmer) in PHP and Javascript.

<?php 

/* date_default_timezone_set('Asia/Calcutta');

$timestamp = time(); */

//set hours according to the India time

$date = '2021-09-28';

$hour = '13';

$minutes = '14';

$seconds = '0';

?>

<div id="timer"></div>

<script>

//task: get timer details from the previous section and assign them to variables. 

//tip, these are associative arrays accessed as $myArray['data'] 

const countDownDate = <?php 

 echo strtotime("$date $hour:$minutes:$seconds" ) ?> * 1000;

let timeNow = <?php print(time()) ?> * 1000;

// Every second, the countdown will be updated.

let i = setInterval(function() {

 timeNow = timeNow + 1000;

// Calculate the time between now and the end of the countdown.  

let dist = countDownDate - timeNow;

// Calculate the number of days, hours, minutes, and seconds in days, hours, minutes, and seconds.

let numOfDays = Math.floor(dist / (1000 * 60 * 60 * 24));

let hr = Math.floor((dist % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));

let min = Math.floor((dist % (1000 * 60 * 60)) / (1000 * 60));

let sec = Math.floor((dist % (1000 * 60)) / 1000);

// Put the result in an element with the id="timer" attribute.  

document.getElementById("timer").innerHTML = numOfDays + "d " + hr + "h " +

min + "m " + sec + "s ";

// When the countdown is over, type some text. 

if (dist < 0) {

clearInterval(i);

document.getElementById("timer").innerHTML = "TIMER EXPIRED";

}

}, 1000);

</script>