Get ready for college hoops around the clock. First- round action of the 2003 NCAA Basketball Championship begins Thursday, March 20, and goes from noon until midnight on CBS. It’s more of the same Friday, Saturday, and Sunday as 65 teams battle to avoid elimination and win a spot in the Sweet Sixteen, played March 27-30. A quartet of teams moves on to the Final Four in New Orleans, April 5 and 7.