Nothing directly. But if you're going to want to plop a plantation down on the calendar resource (and you usually do want to), the value of the cottage becomes a lot less (as it will have no potential to develop into a town.) Cottage will only get you one extra ; if it's worked long enough to get to a hamlet before being bulldozed for the plantation it will have two extra . So you're usually better off farming the resource before calendar. And you can usually plop the farm down earlier than the cottage.What does Calendar have to do with cottages?