CREATE TABLE table_12171 ("Outcome" TEXT, "Date" TEXT, "Tournament" TEXT, "Surface" TEXT, "Partner" TEXT, "Opponents" TEXT, "Score" TEXT)

The tournament with the opponent of Kelly De Beer Eva Pera was played on what date?
SELECT "Date" FROM table_12171 WHERE "Opponents" = 'kelly de beer eva pera'
SELECT "Date" FROM "table_12171" WHERE "Opponents" = 'kelly de beer eva pera'