Calendrical Calculations, II: Three Historical Calendars

From a chronological point of view the substitution for the mean calendaric system of one based on the true movements of the sun and moon, was anything but an improvement, as it destabilized the foundations of the time reckoning. Indeed, the system may have had the charm of adapting daily life as nearly as the astronomical knowledge permitted to the movement of the heavenly bodies, but on the other hand it broke ties with history, as there was no unity either of elements or systems. The very complexity of the system is a proof of its primitiveness.