user: Question: What was the date of the game with a decision of Niittymaki and when the Flyers had a record of 30–21–5?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Decision', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['February 2', 'Anaheim', '0 – 3', 'Philadelphia', 'Biron', 19822.0, '29–17–5']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Decision" = 'Niittymaki' AND "Record" = '30–21–5';