Change the WooCommerce Delivery Slots by Iconic maximum selectable date dynamically based on time

snippet.php

<?php

/**
 * Change maximum delivery date.
 * https://iconicwp.com/products/woocommerce-delivery-slots/?utm_source=Iconic&utm_medium=Gist&utm_campaign=max-selectable-date
 *
 * @param array $max
 *
 * @return array
 */
function iconic_change_max_delivery_date( $max ) {
	$current_time = current_time( 'timestamp' );
	$ymd = current_time( 'Y-m-d' );
	$offset = get_option( 'gmt_offset' ) * HOUR_IN_SECONDS;
	$start = strtotime( $ymd . ' 21:10:00' ) + $offset;
	$end = strtotime( $ymd . ' 23:59:59' ) + $offset;

	// If time is not between start and end, return default settings.
	if ( $current_time < $start || $current_time > $end ) {
		return $max;
	}

	// Add 1 days. (Enables next day delivery).
	$days_to_add = 1;

	// This filter returns an array containing the days to add and a timestamp.
	return array(
		'days_to_add' => $days_to_add,
		'timestamp'   => strtotime( "+" . $days_to_add . " day", current_time( 'timestamp' ) ),
	);
}

add_filter( 'iconic_wds_min_delivery_date', 'iconic_change_max_delivery_date' );