Where is it written that a quarter of a year has anything to do with how a business should be managed? Most business cycles last for years, and even a recession or a downturn usually lasts longer than 90 days. There are few product lifecycles that can happen within 90 days, and in most businesses a 30 to 45 day period exists between an order and payment for that order, so even an order to payment cycle may last longer than 90 days.