The list of daily jobs refreshes every three hours. You get a new set of daily jobs whenever the timer is reset.
A word of caution, though. If you use multiple sets to add new jobs, but, for whatever reason, you don't manage to complete all of them before the timer gets reset, then all of your incomplete jobs will be reset.
In other words, when the timer resets, you'll have five basic jobs plus any extra granted by your VIP status, while all incomplete jobs will be removed from the menu.