This check:
<?php if ( current_user_can( $taxonomy->cap->edit_terms ) ) : ?>
needs to be satisfied to display the “Add New Category” link.
You can set the capabilities for your schedule_day_taxonomy
taxonomy, when you register it.
Example
Only users with the edit_schedule_day_taxonomy
capability can edit the taxonomy:
add_action( 'init', 'schedule_day_tax_func' );
function schedule_day_tax_func() {
register_taxonomy(
'schedule_day_taxonomy',
'post',
array(
'hierarchical' => true,
'label' => 'Day',
'query_var' => true,
'capabilities' => array(
'edit_terms' => 'edit_schedule_day_taxonomy',
),
)
);
}
Without this capability, users can’t edit this taxonomy. If you need to edit it, you can remove this from the code above or assign it to your admin user.