Some counties are 5 days..
Is it a long gun or pistol? Long gun: if he has a hunter safety card or is a fudd like me with a hunting license he can pick up same day.
From same link that Kissfan posted
"(2) The waiting period does not apply in the following circumstances:
(a) When a firearm is being purchased by a holder of a concealed weapons permit as defined in s. 790.06.
(b) To a trade-in of another firearm.
(c) To the purchase of a rifle or shotgun, upon a person’s successfully completing a minimum of a 16-hour hunter safety course and possessing a hunter safety certification card issued under s. 379.3581. A person who is exempt from the hunter safety course requirements under s. 379.3581 and holds a valid Florida hunting license is exempt from the mandatory waiting period under this section for the purchase of a rifle or shotgun."