PART I. ELEMENTS OF THE CALENDAR. DEFINITIONS

I. I. The number of calendars in use among the many civilizations of our globe, past and present, is legion. However, notwithstanding their diversity they all have, or at one time had, two main elements in common: a lunar serving to define smaller, not strictly equal, units of time, and a solar measuring the “year”, i.e., the cyclical recurrence of the seasons. Evidently, the latter alone is of importance to agriculture and thus meets the practical needs of a higher stage of civilization, while the former, being of little practical value, could in theory have been dispensed with as soon as a sedentary community had found means and ways to establish a primitive solar calendar. But in practice, such a radical break with tradition occurred only in exceptional cases.

In point of fact, of all calendars known in history there are only four that were – or at least were intended to be – oriented by the Sun alone: the Egyptian, the Achaemenian Later Avestan, the Julian-Gregorian and that developed by the central-American Mayas and later adopted by the neighbouring Aztecs. But even in the Egyptian and in the Julian calendars, as still in our modern Gregorian, the lunar element is not suppressed completely. As is well-known, it plays a decisive role in the determination of Easter, which fact bears witness to the importance of the religious element even in the most recent phase of a multi-millenary evolution. For at all times and places we find that calendar and religion form an inseparable unity.