user: Question: Name the date for Grass surface for Quarterfinal at the NSW Building Society Open tournament
Columns: ['Tournament', 'Date', 'Surface', 'Round', 'Opponent']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['U.S. Indoor Championships', 'Feb 20–26', 'Carpet', '1st Round', 'Nancy Yeargin']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Surface" = 'Grass' AND "Round" = 'Quarterfinal' AND "Tournament" = 'NSW Building Society Open';