Since it's always nice and sunny (with occasional! showers and snow), I don't think there's place for a dark night in the game...right?

Technically you can't if you don't have the spell. There is a night version and it's in a form of spell, as far as I know there is only 1 player who has this and it's Aeoshattr. Maybe send him a message if you require nightfall in MD for your quest or any other strong reasons.

I am looking forward to see more spoiler sort of answers here.

Bringing the night in MD...that's blasphemy! I always like it hot and sunny, although the question I get is invariably 'What are you, a lizard?'.

But where there is sun, there is also a moon, where there are the Soldiers of Inner Sun, there are...their counterparts. The (permanent?) Sun was made a symbol in MagicDuel, but that didn't stop Mur from giving Night a place in here as well. It didn't stop him from giving the Children of the Eclipse a place in the alliance ranks. It didn't stop him from creating a dream interface and people who can dream while it's hot and sunny.

You'll have to ask him why, but! if you are interested in the Night specifically, I heard the Illusionist Desk in the East can help you ..uh...become more confused? There's a riddle there and solving it will make you see Night for what it is. You may even bring the Night for others as well?