Register core WordPress taxonomies on "Events" post type

// Registers core WordPress category and taxonomy  taxonomies on the "Events" post type registered by the plugin "The Events Calendar"
add_action( 'init', 'ac_add_calendar_taxonomy', 20 );
function ac_add_calendar_taxonomy() {
    register_taxonomy_for_object_type('category', 'tribe_events');
    register_taxonomy_for_object_type('post_tag', 'tribe_events');
}