A city that gives you nothing at the door and everything four paces past it, which is a habit I have come to admire.
One entry does not need a whole day. It needs a cold morning and the patience to stand in a courtyard doing nothing.
Dar Si Said takes rather longer than its size suggests, because the whole thing is ceilings and doors and you spend most of the visit with your head tipped back. Go at opening, when the courtyard is still cold and the woodwork is not competing with anybody's conversation.
The medina lanes do not obey maps and I have stopped resenting them for it. Walk out of the house in any direction for twenty minutes without a destination; every blank wall you pass has a courtyard behind it, and knowing that changes how the whole quarter reads.
February is when I went and February is what I would advise: cold mornings, thin clear light dropping straight down into the courtyards, and cake still available at eleven, which is the only crowd measure I trust.