user: Question: What is the broadcast date when 8.3 million viewers watched?
Columns: ['Episode', 'Broadcast date', 'Run time', 'Viewers (in millions)', 'Archive']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['" Episode One "', '19May1973', '25:55', '9.2', 'PAL 2" colour videotape']
SQL:

assistant: SELECT "Broadcast date" FROM "Table" WHERE "Viewers (in millions)" = '8.3';