user: Question: What was the date of vacancy when Viorel Moldovan replaced a manager?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Rapid Bucureşti', 'Marian Rada', 'Contract not renewed', '3 Cannot handle non-empty timestamp argument! 2008', 'José Peseiro', '3 Cannot handle non-empty timestamp argument! 2008']
SQL:

assistant: SELECT "Date of vacancy" FROM "Table" WHERE "Replaced by" = 'Viorel Moldovan';