Fixed departure enable/disable.

Source

File: /inc/helpers.php
Used by: /inc/helpers.php, /inc/template-functions.php,
/inc/admin/views/tabs/tab-contents/itineraries/price.php

Parameters
$fixed_departure

Example:

function prefix_wp_travel_fixed_departure_defalut( $fixed_departure) {
    return ‘no’;
}
add_filter( 'wp_travel_fixed_departure_defalut', 'prefix_wp_travel_fixed_departure_defalut' );