CREATE TABLE table_12032 ("Race" TEXT, "Length" TEXT, "Class" TEXT, "Circuit" TEXT, "Date" TEXT)

Which date was a GTS class on the Mosport International Raceway?
SELECT "Date" FROM table_12032 WHERE "Class" = 'gts' AND "Circuit" = 'mosport international raceway'
SELECT "Date" FROM "table_12032" WHERE "Circuit" = 'mosport international raceway' AND "Class" = 'gts'