September is not too late, I know a few people in my dental school class that took the test in October or even November. If you have a high GPA and you do well on the DAT, when your submit your application doesn't matter as much. However, it would definitly help improve your chances if you get your DAT done sooner, ideally by mid August or earlier. While schools accept applications until January or later, most schools start reviewing applications at the beginning of August and start interviewing at the end of September / early October. Your application will not be reviewed by schools until everything is received, including your DAT, so the sooner you have everything done the better the chance of an interview and acceptance you will have. Interview slots may be open until February or even March, but the later your get everything in, the more competition you will have for fewer interview spots.
