“And you shall sow the eighth year, and eat of the fruits, the old store; until the ninth year, until its fruits come in, you shall eat the old store.”
Thus in the seventh and the eighth years they would eat ‘the old store', that which had been laid up in the sixth year.
Others see ‘the seventh year' in Leviticus 25:20 as referring to the forty ninth year. But it should be noted that the ‘fiftieth year', the year of Yubile, does not begin at the beginning of the year, the first day of the first month (Abib), but begins on the tenth day of the seventh month, the Day of Atonement, and thus half way through the year, presumably of the forty ninth year commencing on the first of Abib. It is thus only loosely called the ‘fiftieth year', for it is a year beginning at a different date.
This is quite in accord with usage in those times when calendars were not strictly worked out. But to speak then of an eighth and ninth year in terms of it would be confusing to say the least. The first year of the new Yubile period probably began in the fiftieth year as well, so that the ‘fiftieth year' spanned the last part of the forty ninth year and the first part of the following first year which began the new forty nine year period. This would mean that sabbatical years, as we would expect by comparison with the Sabbath, would continue to be on the seventh year as numbered from the previous seventh year without the arrival of the ‘fiftieth year' changing the sequence. The ‘fiftieth year' was thus not an agricultural year, in accord with the other years, but a year of accounting on a different basis, in which grand release took place.