The short answer
Three to four nights in Marrakech makes a romantic short break. For a full honeymoon, seven days lets you add the Atlas, Aït Ben Haddou and two nights at a Sahara camp, and ten days adds a slow finish in Essaouira on the coast. Spring and autumn are the best months.
In more detail
For a short break, three to four nights is the sweet spot: two days to wander the medina, gardens and souks at an easy pace, an evening in the Agafay desert, and a slow morning by the riad pool before you leave.
For seven days, a classic route is two nights in Marrakech with a hammam for two and a rooftop dinner, one night over the Atlas at Aït Ben Haddou, two nights at a desert camp, and one night back in Marrakech before your flight from RAK. The Sahara nights give you a sunset on the dunes, a private camp dinner and a sunrise camel ride.
For ten days, add two nights in Essaouira at the end. The Atlantic wind, the white ramparts and the seafood make a calm finish after the desert.
Avoid July and August, when inland Marrakech regularly tops 40°C. Winter is lovely in the city, though desert nights are cold. Our trips are private, so every day runs at your pace; tell us your dates and we will build it.