Change post title to date if no title is provided

functions.php

<?php
// Do not include the opening php tag.

//* Change post title to date if no title is provided
add_filter( 'wp_insert_post_data', 'crt_update_blank_title' );
function crt_update_blank_title( $data ) {

	$title = $data['post_title'];
	$post_type = $data['post_type'];
	
	if ( empty( $title ) && ( $post_type == 'post' ) ) {

		$timezone = get_option('timezone_string');
		date_default_timezone_set( $timezone );
		$title = date( 'Y-m-d H.i.s' );
		$data['post_title'] = $title;

	}

	return $data;

}