Apart from the relation of the sacrifice of Christ’s death to the Jewish Passover, and its dogmatic signification, sentiment and mere human feeling would have led Christians to regard with reverence the day on which our Lord, the Founder of the Church, died, and to keep the day sacred in each succeeded year on which He had offered the sacrifice of Himself. But for this it was necessary, in the first place, to know on what day exactly His death had taken place.
For the Jews, this was easy; it was the 15th Nisan in their Calendar, but for Christians of other countries, it was very difficult. In the Roman Empire, to which they all belonged, different methods of reckoning time and different calendars were in use. Since 45 B.C., the Romans themselves used the revised Julian Calendar, leaving at the same time perfect freedom to subject nations either to adopt it, or continue their own methods.[102] Chief among the existing systems were the Egyptian, the Syro-Macedonian, and the Semitic, each with its own way of dating the year. The two first systems admitted of being brought into agreement with the Roman Calendar, with more or less difficulty, since, according to them, the year began on a fixed date, but with the Jewish Calendar it was not so, for its was based on the lunar year, and never synchronised with the solar year as to the beginning of months and years. The Egyptian year, at the commencement of the Christian era, began on the 29th August, and consisted of twelve months of thirty days each, and five additional days (ἐπαγόμεναι) belonging to no month. Every fourth year was a leap-year, namely the third, seventh, eleventh, fifteenth year, according to the Julian reckoning. The Syro-Macedonian Calendar commenced with the autumnal equinox. The Syrians, however, later on, partially adopted the Julian Calendar in a somewhat modified form.[103] The Egyptian system of introducing additional days was essentially the same as the Roman, except that their leap-year was always one year in advance of the Roman leap-year. To their usual five additional days, they added yet one more, making a total of six. Consequently the next year, i.e. the fourth, eighth, twelfth, sixteenth, etc., began on the 30th instead of the 29th August.[104] For reckoning years, the Egyptians made use of the years of the sovereign’s reign, but as they began the year with the 1st Thoth, preceding the proclamation of the sovereign’s accession, it often happened that more years than he was entitled to were set down to one sovereign, while another who had reigned for less than a year was simply passed over.[105]
It was extremely difficult for those nations, whose Calendars were arranged on a different system, to fix the day of Christ’s death by their own chronology, for the Jewish 15th Nisan might fall on widely different days, sometimes in March, sometimes in April. How difficult it was to discover, the days on which the death and resurrection of Christ ought to be commemorated, will become more obvious from what follows.
3. The circumstances which led to Easter being a movable Feast
To the real and historical connection between the Christian Easter and the Jewish Passover, is due the explanation of a striking peculiarity in the Church’s year, viz., the movable feasts, of which Easter is the starting-point. Easter falls on no fixed date, because the Jewish 15th Nisan, unlike the dates of the Julian and Gregorian Calendars, varied year by year. The extent and nature of this discrepancy are caused by the Semitic Calendar. At the commencement of the Christian era, this Calendar was not only used by the Jews, but also extensively followed in Syria, Arabia, Mesopotamia, Babylon, Armenia, Osrhoëne, and in a great part of Asia Minor, although other nationalities in these countries kept each to its own Calendar. Thus, for example, the Greeks in Antioch followed the Syro-Macedonian Calendar, and so on. Where a mixed population existed in any place, different Calendars would be found in use.
The special features of the Semitic, or Jewish Calendar, which concern us in this connection are the following:—
1. The Jewish day ended at sunset, and so the evening hours, from about six p.m. belonged to the following day. This caused difference in dates, for what happened according to Roman ideas at ten p.m. for example, was regarded by the Jews as happening on the following day.
2. The Jewish year was a variable lunar year, i.e. it consisted of twelve months, each of which began with the new moon, the full moon consequently falling on the 14th of each month. The moon completes her orbit round the earth in twenty-nine and a half days, or two orbits in fifty-nine days. The Jewish months, accordingly, varied from twenty-nine to thirty days alternately (Tischri and Nisan having thirty days), it being impossible to commence a month in the middle of a day. Thus the twelve months of the Jewish year make up 354 days. Eleven and a quarter days were required to make up the length of a solar year. Had this discrepancy not been rectified in some way, every Jewish month, and the new year as well, would, in the course of thirty years, have made the circle of the year. For, if in one year, the 1st Nisan coincided with the 1st March, in the next it would fall on the 12th, and so on.
The Semites brought about the necessary adjustment, not by leap-years, but by the insertion of an additional month. For example, eight solar years have a total of 2920 days, not counting the addition days of leap years. The same number of days make up ninety-nine lunar months, or, in other words, eight lunar years and three intercalary months, are equal to eight solar years. Thus, in eight years, three additional months must be introduced, making the number of days almost equal with the days of eight solar years, except for a small discrepancy, caused by the additional day in leap year. When these additional days had reached the number of thirty, they could be accounted for by the introduction of a further additional month. In regulating these points, the equinoxes were of the utmost importance, and, in the second place, the ceremonial oblation of the first fruits.