Conversation so far:
What was Rubin Carter convicted of the first time?
In 1966, police arrested Rubin Carter and friend John Artis for a triple homicide committed at the Lafayette Bar and Grill in Paterson, New Jersey.
Was Rubin Carter guilty of the first conviction?
The evidence surrounding the case was lacking and the witnesses couldn't keep their story straight. It was unclear whether Rubin Carter did the crime or not.
How long did Rubin Carter spend in prison?
Rubin Hurricane Carter was an American-Canadian boxer who was wrongfully convicted of murder and later released following a petition of habeas corpus after serving almost 20 years in prison.

Question: What date did he get out of prison?
Self-contained rewrite: What date did Rubin Carter get out of prison?