In the following series of articles, I hope to describe an old Hebrew luni-solar calendar which, if understood properly, adds considerable light to our understanding of the scriptures.
The modern Jewish calendar, as we now know it, is not the same as the one described in ancient Hebrew literature. It went through an evolutionary change from about the Persian – Greek period, probably to comply with the governing empires of that time. Commentators are aware of these changes and influences, but are hazy concerning the details of that from which it came. Leap years, for example, are not explicitly mentioned in the Bible, so it is assumed they were inserted in much the same way as a second Adar is now, albeit by primitive observation of seasons.
Modern Jewish timekeepers no longer physically observe moons, but use a formula-based method instead, to intercalate months. It was settled by Hillel in the fourth century (AD 359), and it was, for all intents and purposes, the same as that devised by the Greek astronomer, Meton of Athens, (432 BC) whose name is synonymous with luni-solar calendars. It would be fair to say that all luni-solar calendars currently being used are ‘Metonic’ including the Chinese, although the latter may wish to argue that theirs is older.
Meton discovered his cycle in 432 BC when he noticed that 235 synodic months almost exactly equals 19 solar years. Therefore, a thirteenth month is added to the lunar year on the 3rd, 6th, 8th, 11th, 14th and 17th years, of a 19-year cycle. In so doing, the lunar cycle is synchronised with the solar. It is an effective system, and it is not my purpose to criticise it. However, there is evidence to show that, in addition to the actual sighting of new moons, the original Hebrew calendar used advanced astronomical formulae too.
The following reconstruction describes an old luni-solar system which synchronised the heavenly bodies regularly per seven years, and again in the forty-ninth year. Following that, another forty-nine year cycle would repeat using the same formula. It may well be that the pre-metonic Hebrew calendar was even more excellent than the one which developed after.