Hi there! I was in your situation a year ago...but not with the DAT, another test...I had planned to study the summer before my fourth year, but did not get to it. Then I planned to study during winter break...did not get to it. Knowing I was in BIG TROUBLE, I studied for a grand total of four weeks for aforementioned test over spring break and the first few weeks of the quarter before taking this test and doing very AVERAGE. My heart was not into this profession at all, because I couldn't even motivate myself to study for that test...my GPA wasn't even a 3.6 at the time, I barely pulled it to a 3.6 by the end of my third year, and knowing how competitive the application process is, I said "screw it."
Needless to say my heart has always been with the dentistry profession, whether I wanted to admit it or not, a profession I had intended to pursue upon coming to college. Around June 1, I decided to apply to dental schools, having no letters, no transcripts, no DAT score ("there are three scores?!"). I scrambled around for all of this stuff near the end of June and was also writing my personal statement. Meanwhile, I started studying my BUTT off around June 15 for the DAT that would take place on Aug 13. I was VERY motivated, mainly because I was taking such a risk by applying with no score. I was missing a fourth letter, which I got in like...2 weeks ago.
Anyways, I have 6 interviews so far... Believe me, if I can do it, it is DEFINITELY possible for you to study for two months and get your stuff together. Especially with the pressure, if you're good working under that. Not to mention you are in a much better position than I am, better GPA, letters done...summer is a bonus because there are no classes you have to worry about. However, you are banking on your DAT scores- mine turned out rather good, so the fact that I applied late didn't matter too much at the end. It depends on how confident you are in your abilities. However, four weeks is not sufficient, in my opinion. It takes like a month to go over material, and a month of practicing while reviewing and touching up on things you forgot from the first month.
[How I studied was I did two subjects a day, whether it was problems or reading. Just alternate, or whenever you get bored. Do bio at the beginning and end. Do the chem first. Most important are practice tests and GOING OVER THOSE PROBLEMS! Believe me, I got destroyed in the practice tests...going over the answers is what raised my score in the final test (the only one that matters). For me, if I study too early, i remember jack later on. I read examkrackers MCAT books, AP Barrons Chem and Bio, the KAPLAN DAT...blah blah.]
*edit* sorry for long post...