This wouldn't be pronounced DAHN-te (long 'ah') in Italian, which does not use the longer vowel. It would be DAN-te. But American pronunciations can go as far as dawn-TAY.
In Italian, the vowels A, E, I, O, and U are pronounced AH, A, E, O, and OO. There is no other pronunciation for these letters like there is in English. This name is absolutely pronounced "DON-tay" in Italian (but of course, no "y" sound, I only put that there for emphasis on the long A).