Automatically Expire WordPress Posts After a Specific Date

/**
 * Automatically expire posts based on a custom field.
 *
 * Custom Field Key:
 * post_expiry_date
 *
 * Date Format:
 * Y-m-d (Example: 2026-12-31)
 */

add_action( 'wp', 'wpfolks_expire_scheduled_posts' );

function wpfolks_expire_scheduled_posts() {

	if ( ! wp_next_scheduled( 'wpfolks_check_expired_posts' ) ) {
		wp_schedule_event( time(), 'hourly', 'wpfolks_check_expired_posts' );
	}
}

add_action( 'wpfolks_check_expired_posts', 'wpfolks_process_expired_posts' );

function wpfolks_process_expired_posts() {

	$args = array(
		'post_type'      => 'post',
		'post_status'    => 'publish',
		'posts_per_page' => -1,
		'meta_query'     => array(
			array(
				'key'     => 'post_expiry_date',
				'compare' => 'EXISTS',
			),
		),
	);

	$posts = get_posts( $args );

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

	foreach ( $posts as $post ) {

		$expiry_date = get_post_meta(
			$post->ID,
			'post_expiry_date',
			true
		);

		if ( ! empty( $expiry_date ) && $expiry_date <= $today ) {

			wp_update_post(
				array(
					'ID'          => $post->ID,
					'post_status' => 'draft',
				)
			);
		}
	}
}