\WP_Stager_Integration\Event::filter_event_date(string|int $date, string $format, WP_Post $post): string|int|false

Full Code

/**
 * Filters the event date.
 *
 * @param string|int $date   Formatted date string or Unix timestamp if $format is 'U' or 'G'.
 * @param string     $format PHP date format.
 * @param WP_Post    $post   The post object.
 *
 * @return string|int|false Date the current post was written. False on failure.
 */
public static function filter_event_date( $date, $format, $post ) {

    // Bail if not an event post
    if ( $post->post_type !== self::CPT_SLUG ) {
        return $date;
    }

    // Get programStartAt meta
    $meta_key         = (string) (self::get_meta_key( self::META_KEY_TIMESTAMP_PROGRAM_START ) ?: '');
    $program_start_at = (int) (get_post_meta( $post->ID, $meta_key, true ) ?: 0);

    // Bail if no programStartAt meta
    if ( ! $program_start_at ) {
        return $date;
    }

    // Format date
    return wp_date( $format, $program_start_at );
}