user: Question: What day did the record reach 15-4?
Columns: ['Date', 'Opponent', 'Score', 'Loss', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['April 6', '@ Tigers', '4 - 2', 'Gullickson (0-1)', 51068.0, '1-0']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Record" = '15-4';