WordPress: update post dates based on post meta value (used for radio series to change dates from rerun airdate to original airdate)

wp_new_post-dates.php

<?php

// Get category posts.
$query_args = array(
    'category_name'  => 'episode', // Name of category.
    'posts_per_page' => 50, // Do in bathces to avoid overloading server.
    'offset'         => 0, // Skip previous batch by incrementing by 50 each time run.
);
$query = new WP_Query( $query_args );

// Update post dates and write redirect directive for htaccess file.
foreach ( $query->posts as $post ) {
    $new_date = get_post_meta( $post->ID, 'airdate2', true ); // Date to use, in format Y-d-m.

    if ( $airdate2 ) {
        $new_date = $new_date . ' 00:00:00'; // WP date format: Y-d-m H:i:s
        $new_date_gmt = get_gmt_from_date( $post_date );
        
        // Write redirect directive with old URL.      
        echo 'RedirectPermanent ' . get_permalink( $post->ID )  . ' '; 

        $args_update = array (
                'ID'            => $post->ID,
                'post_date'     => $new_date,
                'post_date_gmt' => $new_date_gmt,
        );
        wp_update_post( $args_update ); // Set new post date.

        // Add new URL to directive.
        echo get_permalink( $post->ID ) . '<br>';
    }
}
?>