Kay,
   I would answer this personally, but I can't find your email address. You have quoted Rabbi Shraga Simmons that the first Jubilee was in the year 1222 B.C.E. Unfortunately he is not correct. He should look in his own Talmud and he would find a record of Jubilees. According to the Talmud, the 16th Jubilee occurred in the year 623-622  B.C. which was 18th year of king Josiah in the year of his Great Passover. In harmony with this dating, the Talmud also states that Ezekiel's temple vision was given in the 17the Jubilee in the year 574-573 B.C. Thus counting back we find the first Jubilee after the Israelites  came into the land was 1358-1357 B.C. Jubilees are counted in 49-year increments, thus counting back 49 more years puts the crossing of Jordan and the entrance into the land in 1407-1406 B.C.
   I know that the theory is that if we could find the beginning date, and count in 49-year increments, we could find where we are now in relation to the Jubilees. Unfortunately this is not so. Since the Sabbath and Jubilee Years were for the "land" they began a new count when they returned to the land from their Babylonian captivity. They have continued this new count for all the centuries until now. However, since the Jubilees are for the land, they also celebrated a new Jubilee in A.D. 1998, which was 50 years from 1948.
   The original Jubilee count is also confirmed by a solar eclipse in the year that Hezekiah asked for a sign, and the sundial went back by ten degrees. That sundial was really a set of steps which cast a shadow, used for recording the hours of the day. The only natural phenomenon which will make a sundial wobble in this way is a solar eclipse. And there was one on that very day in history. It can be found on an eclipse calendar on March 5, 702 B.C. which was in the 14th year of Hezekiah. We know this was a Sabbath year because God told Hezekiah that they would not be planting and reaping. This Sabbath year was not followed by a Jubilee year because it was not a 7th Sabbath year, however it follows the sequence of the count perfectly.
 
Bonnie Gaunt