All columns are filed with a 'k' category code. For questions about this schedule, call 212-556-1927. September 1: David Brooks, Bob Herbert September 2: Maureen Dowd, (Thomas L. Friedman on vacation) September 3: Gail Collins, Nicholas D. Kristof September 4: David Brooks (Paul Krugman on vacation) September 5: Collins, Herbert September 6: Dowd, Kristof (Friedman, Rich on vacation) September 7: (Krugman on vacation) September 8: Brooks, Herbert September 9: Dowd, Friedman September 10: Collins (Kristof on vacation) September 11: Brooks (Krugman on vacation) September 12: Collins, Herbert September 13: Dowd, Friedman, Kristof, Rich September 14: Ross Douthat (Krugman on vacation) September 15: Brooks, Herbert September 16: Dowd, Friedman September 17: Kristof (Collins on vacation) September 18: Krugman, Brooks September 19: Collins, Herbert September 20: Dowd, Friedman, Rich (Kristof on vacation) September 21: Krugman September 22: Brooks, Herbert September 23: Dowd, Friedman September 24: Collins (Kristof on vacation) September 25: Krugman, Brooks September 26: Collins, Herbert September 27: Dowd, Friedman, Rich (Kristof on vacation) September 28: Krugman, Douthat September 29: Brooks, Herbert September 30: Dowd, Friedman 