user: Question: When was Pablo Andújar the opponent?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['30 May 2006', 'Turin , Italy', 'Clay', 'Marcel Granollers', '6–3, 6–3']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Opponent" = 'Pablo Andújar';