Q. You once said that if God intends to make the rapture coincide with a Jewish feast day then the most likely by far would be Pentecost(Shavuot).”
I realize we are only speculating here, but I believe that the Day of Atonement (Yom Kippur) could also be a likely candidate. It is probably the most holy feast of the seven feasts. God told the Jews to spend evening to evening afflicting their souls (fasting, praying, confessing, sacrificing, etc.; Lev. 23:32).