user: Question: What is Date, when Tournament, is Greenbrier Classic?
Columns: ['Date', 'Tournament', 'Winning score', 'Margin of victory', 'Runner(s)-up']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['16 Mar 1997', 'Honda Classic', '−14 (68-68-67-71=274)', '1 stroke', 'Michael Bradley , Payne Stewart']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Tournament" = 'Greenbrier Classic';