Question: When were they trained in that procedure? | Do you mean the certification date and the expired date of the procedure named Complete Walletectomy? | The certification date.
SQL: SELECT T2.CertificationDate FROM physician AS T1 JOIN trained_in AS T2 ON T1.employeeid   =   T2.physician JOIN procedures AS T3 ON T3.code   =   T2.treatment where T3.Name = 'Complete Walletectomy'