user: Question:  what's the date where visitor is Phoenix Suns and record is 31–30
Columns: ['#', 'Date', 'Visitor', 'Score', 'Home', 'Leading scorer', 'Attendance', 'Record', 'Streak']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [60.0, 'March 2', 'Portland Trail Blazers', 'L 104–110', 'Golden State Warriors', 'Jackson : 29', 'Oracle Arena 19,596', '31–29', 'L1']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Visitor" = 'Phoenix Suns' AND "Record" = '31–30';