Shogun 2 & Rise of the Samurai
Each turn represents one of the four seasons: spring, summer, autumn and winter - so there are four turns per year. In Fall of the Samurai each turn represents a two week period. To check the season in Shogun 2 and Rise of the Samurai, mouse over the end turn button in the bottom right-hand corner of the screen. The date is written on the end turn button itself.
Fall of the Samurai
In Fall of the Samurai, turns represent a two week period. To check the date, mouse over the end turn button at the bottom right-hand side of the campaign map.