CREATE TABLE table_52874 ("Date" TEXT, "Score" TEXT, "Set 1" TEXT, "Set 2" TEXT, "Set 3" TEXT, "Total" TEXT)

What is the Date with a Set 1 with 15 1?
SELECT "Date" FROM table_52874 WHERE "Set 1" = '15–1'
SELECT "Date" FROM "table_52874" WHERE "Set 1" = '15–1'