CREATE TABLE table_32720 ("Date" TEXT, "Tournament" TEXT, "Surface" TEXT, "Opponent in the final" TEXT, "Score" TEXT)

On what date did the match against Flavio Cipolla, played on a clay surface, occur?
SELECT "Date" FROM table_32720 WHERE "Surface" = 'clay' AND "Opponent in the final" = 'flavio cipolla'
SELECT "Date" FROM "table_32720" WHERE "Opponent in the final" = 'flavio cipolla' AND "Surface" = 'clay'