No, Petrificus Totalus or the Full-Body Binding Curse does not wear off on its own. It can only be lifted by using countercurses like Episkey and Reparifors or using Finite Incantatem to prevent the curse from hitting the victim. Another option is to use the Anti-Paralysis potion. Finally, the only time the curse lifts off on its own is when the caster of this curse dies. This happens when Dumbledore dies as Harry is freed from the curse that Dumbledore cast on him to protect him from the Death Eaters atop the Astronomy Tower.