user: Question: Which date has a Race Leader of Hermann Buse ( GER ), and a Stage of 5?
Columns: ['Stage', 'Date', 'Course', 'Distance', 'Winner', 'Race Leader']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1', '14 May', 'Milan to Vicenza', 'km (mi)', 'Learco Guerra ( ITA )', 'Learco Guerra ( ITA )']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Race Leader" = 'Hermann Buse ( GER )' AND "Stage" = '5';