I think it would be nice if instead of getting a message on the first of december saying "winter has started" there would be a message that says something like "the colonists agree that winter has come" or "Spring has finally sprung!" or "Summer is here!" or "Fall is falling". Also if it could be triggered by environmental conditions rather than a set calendar would make it more realistic since your colonists wouldn't know the exact date to trigger the messages. For example say it's late winter not yet spring and the volcanic winter event triggered, it would be more realistic for spring to be delayed rather than getting a message "spring has come". Since I play northern temperate forest (I'm an Alaskan, I play what I know) I think it's silly to get "winter has started" while I've been already in winter conditions for a month or so and that goes for in real life too.