- September 1, 1991 (This strip is adapted in Lucy Must Be Traded, Charlie Brown)
- September 2, 1991
- September 3, 1991
- September 4, 1991 (This strip is adapted in the video game, Get Ready for School, Charlie Brown!)
- September 5, 1991
- September 6, 1991
- September 7, 1991
- September 8, 1991
- September 9, 1991
- September 10, 1991
- September 11, 1991
- September 12, 1991
- September 13, 1991
- September 14, 1991 (The 1st panel in this strip is used on the page for July 18 of the Dayspring Peanuts A Year's Worth of Smiles and Blessings Desk Calendar)
- September 15, 1991
- September 16, 1991
- September 17, 1991
- September 18, 1991
- September 19, 1991
- September 20, 1991
- September 21, 1991 (This strip is used on the page for September 16 of the Dayspring Peanuts A Year's Worth of Smiles and Blessings Desk Calendar)
- September 22, 1991
- September 23, 1991
- September 24, 1991
- September 25, 1991
- September 26, 1991 (The day that A Boy Named Charlie Brown was re-released on VHS) (Sally develops a new philosophy)
- September 27, 1991
- September 28, 1991
- September 29, 1991 (Football gag for 1991)
- September 30, 1991
← August 1991 | October 1991 → |