Actually, I didn't study at all for the DAT the first time I took it. I was still in limbo between med school and dental school (i.e. torn between becoming an ENT surgeon and an OMS). So, I took a prep class for the MCAT, took the MCAT, and then took the DAT a week later. About a month later I realized that I wanted to be an OMFS, mainly because they get to administer their own anesthesia. Long story long, I didn't apply to med school that year, applied to dental school, got rejected. I studied about 2-3 hours a day for two and a half months while working as an OMFS assistant last fall and, voila.
To the OP, I'd strap myself to a chair for about two months, get to know the material inside and out, and go dominate that test.