I just checked, and the payable date is 12 months from the date on the Debenture.
If yours is the same as mine, you should have already received certificates. SEVU issued a memo (mine isn't dated!) sometime last Spring, saying that they were converting all debentures and certs would be issued.
I don't recall the exact date I received the certs, but it was probably early Summer.
BTW, someone from SEVU tried to convince me that the restriction comes off 12 months from the date on the certs. A quick read of the Debenture agreement proves otherwise.
I'm not selling mine, though, either.