The “when due date is approaching…” rules will fire only once daily just after midnight.
If on Thursday you have a task assigned to you and give it a due date of Friday, then at just after 12:01a Friday that Rule for Today rule will fire and should move the task to the today section.
If not, then send us a screenshot of the full rule definition you have.
Also, see detailed info on setting up such rules in my article on My Tasks: