CREATE TABLE table_40633 ("Year" FLOAT, "Division" FLOAT, "League" TEXT, "Regular Season" TEXT, "Playoffs" TEXT, "Open Cup" TEXT)

What regular season did the team reach the conference semifinals in the playoffs?
SELECT "Regular Season" FROM table_40633 WHERE "Playoffs" = 'conference semifinals'
SELECT "Regular Season" FROM "table_40633" WHERE "Playoffs" = 'conference semifinals'