Add countdown on thankyou page

functions.php

<?php

/** 
 * Add countdown into view order and thankyou page 
 * @author: Onnay Okheng (@onnayokheng)
 */
add_action( 'woocommerce_thankyou', 'matamerah_add_countdown_checkout' );
add_action( 'woocommerce_view_order', 'matamerah_add_countdown_checkout' );
function matamerah_add_countdown_checkout($order_id = 0)
{
	if ($order_id == 0) {
		return false;
	}

	// Get object order
	$order = wc_get_order( $order_id );

	// Check if order is null
	if ( is_null($order) ) {
		return false;
	}

	// Check if order status is not on-hold or pending
	if ( !in_array($order->get_status(), array('on-hold', 'pending') ) ) {
		return false;
	}
	$order_date 	= wc_format_datetime($order->get_date_created(), 'Y-m-d H:i');
	$date_time 		= strtotime($order_date . " + 1 day");

	$new_order_date = mysql2date( get_option( 'date_format' ), date('Y-m-d H:i', $date_time) );
	$new_order_time = date( 'H:i', $date_time ); ?>
	<style>
		.container-countdown { position: fixed; z-index: 100; bottom: 0; left: 0; width: 100%; height: auto; background: red; color: white; text-align: center; -webkit-box-shadow: 0px -3px 8px -1px rgba(0,0,0,0.2);-moz-box-shadow: 0px -3px 8px -1px rgba(0,0,0,0.2);box-shadow: 0px -3px 8px -1px rgba(0,0,0,0.2); }
		.container-countdown span { font-size: 1.6rem; padding: 20px 0; display: block; }
	</style>
	<div class="container-countdown">
		<span>Berakhir pada: <?php echo $new_order_date; ?>, pukul <?php echo $new_order_time; ?>.</span>
	</div><?php
}