The guard at the gate will accept hand deliveries, just like sending a courier. But if you are asking if they will let you walk in and give it to a visa officer, that's a big NO. I would have a courier do it because then you have a third party delivery slip with verification of delivery. As far as when deliveries are accepted, anytime during normal business hours as the gate is "manned" then.
Seriously, I would use a courier. They don't like people dropping stuff off. They changed their practice for other temporary visa types about 2 years ago and will no longer accept dropped off applications. The guard could refuse you if he doesn't know the difference between the application types. Don't take the chance of travelling all the way to Rabat only to get the door slammed in your face. There are plenty of good courier services in Morocco you can use.