user: Question: What is the Date of the game against Christo van Rensburg?
Columns: ['Outcome', 'Date', 'Championship', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Runner-up', '25 March 1985', 'Rotterdam , Netherlands', 'Carpet', 'Miloslav Mečíř', '1–6, 2–6']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Opponent" = 'Christo van Rensburg';