Patrick S pointed out that there are places on the Fixed World Map where you get intersections between different time "zones" - which oddly enough echoes recent posts about Lewis Carroll's thoughts on day and night.
To illustrate, if you take the Fixed World Map, you'll notice that there are two places in particular where you get four different zones intersecting: the place where O, P and Q meet, and the place where O, L, M and R meet.
the North part of O (always dawn, always spring - a vast plain dotted with lakes, each ruled by a vodyanoi prince and his human fisherman serfs)
the South part of O (always dawn, always winter - divided between were-raven lords, each of whom acts as a benevolent human lord over his human subjects)
P (always night, always winter - a place where nothing grows, and little lives except xorn and xaren and the hook horrors who hunt them, and the occasional lich, archmage, or secretive undead)
Q (always night, always spring - a land of sverfneblin republics who live off fungus, and the grimlocks and troglodytes who prey on them)
What kind of city would grow up in such a place?
I call it The City & The City & The City & The City in honour of a book by China Mieville which I've never actually read. Here is its map (partially borrowed from here: http://www.armellecaron.fr/):
A is the sverfneblin quarter: a place of many fungus gardens and buildings which extend far below the surface of the earth. The river here is semi-frozen and filled with blind catfish and pale eels which the sverfneblin use to supplement their diet.
B is the vodyanoi quarter: largely populated by humans but containing three or four large lakes, each of which contains a vodyanoi princeling and his family. Being the warmest and lightest quarter of the city, it is also the only place where trees and plants grow, and there are many parks and green places.
C is the were-raven quarter: again, largely populated by humans but ruled by an extended aristocracy of were-raven lords and their families. It frequently snows but the permanent golden light of dawn gives it some warmth; the river flows freely.
D is the dead quarter: a frozen, frigid place where the river is permanently frozen and nothing can grow. It is ruled by a collection of outcast mages, demonologists and necromancers and their various slaves.
The City & The City & The City & The City is a free city, where anybody can come to do trade. Representatives from each of the four quarters meet once each lunar month on the island in the centre of the river. Here they discuss matters of state and renew their vows to maintain peace. Of course, that doesn't stop them plotting against each other and jostling for power on a more-or-less continual basis...