from preamble:

"Change Set: Dates-raok Date: 19 April 2002 Author: Richard A. O'Keefe

My original intent was just to add a few class comments, but I soon noticed a few missing methods (enumerating over the days of a month, for example). That's not all that's missing, a DateInterval class (with Week and Month as subclasses of that instead of Date) is clearly called for. But that's too much refactoring for one morning. I also noticed that the instance creation methods of Date were inherited by Month, and could too easily be used to create invalid Months, so they had to be overridden. Very little has been done to Week; there should be two classes MondayWeek and SundayWeek instead of the 'startMonday' hack.

Date>>previous: appeared to be broken, but Week relied on the breakage, so I have just noted the problem in a comment."!