user: Question: What is the grand final date for the game with a score or 30-24?
Columns: ['Season', 'Grand FinalDate', 'WinningTeam', 'Score', 'LosingTeam', 'Location', 'GF Attendance', 'Clive Churchill Medal']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: [1998.0, '27 September 1998', 'Brisbane Broncos (4)', '38-12', 'Canterbury Bulldogs', 'Sydney Football Stadium , Sydney (11)', 40857.0, 'Gorden Tallis']
SQL:

assistant: SELECT "Grand FinalDate" FROM "Table" WHERE "Score" = '30-24';