The Sabbatical Year Chronology Method
There is a more fundamental reason why sabbatical year chronology is difficult to employ in biblical studies. The Sabbatical Year began on the first day of Tishri and ended on the last day of Elul. Thus the Shemitah year which began in the Fall differed from the civil and religious year which, in preexilic and postexilic times, began on the first day of Nisan in the Spring. During the Second temple period, the Shemitah cycle was not employed for reckoning time except in sectarian circles. Thus a number of chronology studies are flawed in that Tishri is said to be the first month of the year during the Second Temple period.
Yet we need to recognize that the influence of the institution of Shemitah played a major role in the gradual shifting of the beginning of the Jewish New Year from Nisan to Tishri. This shift explains why one cannot create actable of the sabbatical year cycle by beginning with the year of the most recent sabbatical year (5761) and working backwards. This would be an exercise in futility.
In addition, as shown by Don Blosser, “The confusion over Sabbath year dating comes from the difficulty in properly understanding the terminology to describe the crop-food relationship.”[i] Biblical chronology is a fascinating subject that will be addressed in greater detail in future comments.
[i] Don Blosser, The Sabbath Year Cycle in Josephus, Hebrew Union College Annual 52 (1981), 129-139.