"Abruptly enough. Winter doesn't mean immediate snow and freezing to death, but as soon as the season ticks over, the world noticeably changes. I suppose you could say, if the world is a stage, we experience a change in lighting. Winter is desaturated and blue, spring is a vivid green, summers are orange and sepia-toned. Birch trees only drop nuts in the fall. The crops are very particular about these seasonal barriers, and it's impossible to grow giant crops if they're off by even a couple of days."