CREATE TABLE table_3139 ("Week" FLOAT, "Date" CLOB, "Kickoff" CLOB, "Opponent" CLOB, "Final score" CLOB, "Team record" CLOB, "Game site" CLOB, "Attendance" FLOAT)

What week had kickoff time at 6:00 p.m.?
SELECT MIN("Week") FROM table_3139 WHERE "Kickoff" = '6:00 p.m.'
SELECT MIN("Week") FROM "table_3139" WHERE "Kickoff" = '6:00 p.m.'