Why I Moved From Calendar Years to Rolling Market Data Property markets do not move neatly within calendar years. Prices rise and fall continuously, transaction volumes shift month by month, and market momentum can change quickly. Until now, several areas of the site analysed data using fixed calendar years. While this approach is simple to understand, it can sometimes hide what is actually happening in the market today. For example, if the current year is only partially complete, a calendar-year analysis may compare a full year of historical sales with only a few months of the current...