Hides the time field in the booking form. Requires PHP 5.3+

hide-time-for-rtb.php

<?php
/**
 * Plugin Name: Hidden Time Field for Restaurant Reservations
 * Plugin URI: http://themeofthecrop.com
 * Description: Hides the time field in the booking form. Requires PHP 5.3+
 * Version: 1.0
 * Author: Theme of the Crop
 * Author URI: http://themeofthecrop.com
 * License:     GNU General Public License v2.0 or later
 * License URI: http://www.gnu.org/licenses/gpl-2.0.html
 * Requires at least: 4.0
 * Tested up to: 4.01
 *
 * Text Domain: restaurant-reservations
 * Domain Path: /languages/
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
 * General Public License as published by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */
if ( ! defined( 'ABSPATH' ) )
	exit;

add_filter( 'rtb_booking_form_fields', 'rtbht_hide_time', 10, 2 );
function rtbht_hide_time( $fields, $request ) {

	$fields['reservation']['fields']['time']['callback'] = function() {
		echo '<input type="hidden" name="rtb-time" value="12:00 PM">';
	};

	return $fields;
}