I did not mean to imply Jesus waited for the shemitah to forgive our sinful debts, anyone who is truly a Christian knows that our debt was paid in full on Passover, on the first month in Hebrew calendar. It should be the main hold on every Christian's heart. Evidently, Jesus was not crucified on the 29th of Elul.
However, I did mean the aspect of forgiveness on the last day of the seventh year in the Hebrew calendar also known as a shemitah is a foreshadowing of forgiveness.
As touching on the teachings or doctrine that you say Cahn's trying bring people under, I am not familiar with. Possibly because I have not watch many of his sermons, or read any of his books -- I only know about this Shemitah mystery, because of a show I watched on TBN. Every Christian should be aware that we are saved through faith in the Son of God, being under grace, and cannot be justified through the Law.
The point I was trying to make is that prophecy is being fulfilled.
Whether people want to argue about Cahn's teaching, that another topic, but there is no denying that every 29th of Elul of these last two Shemitah years something Biblical has occured. Whether it does make an impact on our own personal finances, we should not be hindered by the fact and keep on holding to our true treasure in heaven!
God bless!