It's been a year since I last took the DAT, so I don't quite remember the break lengths. I heard they changed it this year... can someone pls answer OP's question regarding break length?
Good luck! It is 30 minutes like stated above. However you can resume whenever you'd like during that 30minutes. I took a 15 minute break and then sat back down at the computer chair and couldn't wait another 15 minutes so I clicked resume!