Avodah Zarah

Said R. Huna the son of R. Joshua: If one does not know what the year is in the Sabbatical cycle of seven years,  let him add one year [to that in the era of the Destruction] and let him put aside the hundreds as Jubilee Cycles and convert the remainder into Sabbatical Cycles [of seven years each] after adding thereto two years for every complete century; what is left over will give him the number of the given year in the current Sabbatical Cycle. As a mnemonical sign [for adding two years for every century, think of the verse]. For these two years hath the famine been in the land. Said R. Hanina:  From the year four hundred after the destruction onwards, if one says unto you. 'Buy a field that is worth one thousand denarii for one denar' — do not buy it.  In a Baraitha it is taught: From the year four thousand two hundred and thirty-one of the Creation of the World onward, if one says unto you. 'Buy thee a field that is worth a thousand denarii for one denar,' do not buy it. What difference is there between these two [given periods]? — There is a difference of three years between them, the one of the Baraitha being three years longer. There was [produced in court] a document which was dated