Add grace period to users that enddate falls in august or christmas

gistfile1.php

<?php
 /**
 * Change enddate to a date that is not a holiday give grace period adding more days depending the holidays days.
 * link: TBD
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/

/**
 * Change enddate to a date that is not a holiday give grace period adding more days depending the holidays days.
 *
 * @param int $user_id The user ID.
 * @param object $morder The order object.
 */
function custom_pmpro_after_change_membership_level( $user_id, $morder ) {
	global $wpdb;
	$user = get_userdata( $user_id );
	//get current year
	$year = date('Y');
	//first of august
	$august_start = date('Y-m-d', strtotime( $year . '-08-01' ) );
	//31 of august
	$august_end = date('Y-m-d', strtotime( $year . '-08-31' ) );
	//22 of december
	$december_start = date('Y-m-d', strtotime( $year . '-12-22' ) );
	//6 of january
	$january_end = date('Y-m-d', strtotime( $year + 1 . '-01-06' ) );

	$today = date( 'Y-m-d' );


	//Retrieve memberships user just checked out.
	$memberships_users = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->pmpro_memberships_users WHERE user_id = %d AND status = 'active' AND 
	startdate >= %s LIMIT 1", $user_id, $today ) );

	if ( ! empty( $memberships_users ) ) {
		$enddate = $memberships_users->enddate;
		$should_update = false;
		//Is in august ? Make the end date in september
		if ( $enddate >= $august_start && $enddate <= $august_end ) {
			$enddate = date('Y-m-d', strtotime($year . '-09-01'));
			$should_update = true;
		} else if ( $enddate >= $december_start && $enddate <= $january_end ) {
			$enddate = date('Y-m-d', strtotime($year + 1 . '-01-07'));
			$should_update = true;
		}
		if ( $should_update ) {
			//Update $memberships_users above with new enddate
			$wpdb->update( $wpdb->pmpro_memberships_users, array( 'enddate' => $enddate ), 
			array( 'id' =>  $memberships_users->id) );		
		}	
	}
}

add_filter( 'pmpro_after_checkout', 'custom_pmpro_after_change_membership_level', 10, 2 );