今年のクリスマスにリリースが予定されている Ruby-1.9.1 ですが、 Rails側でも対応の動きがあるようですね。 [PATCH] Ruby 1.9 compatibility Aiming for compatibility with Ruby 1.9. The initial patch is incomplete, though nearly all tests pass. The only substantial breakage is that 1.9 adds a to_time method that converts Time, Date, and DateTime to Time in the local timezone. We have similar methods in Active Support which convert to time in the