Once they start looking at an application. My guess is it takes about 3 to 5 days to decide from there. For example today is the 19th business day for me. I highly doubt they have been looking at it everyday if even looked at it yet lol. Yes "Non Priority" lol.
From what I have read in posts here on the forum before, it only actually takes an hour or two to decide a straightforward application once they have it in front of them (but if you have a criminal conviction, such as your DUI, they do have to look into it, which can add an extra 2-3 weeks onto the processing time).
In the US, they process about 4,000 applications per month, and until recently, there were 3 consulates processing the visas (so about 1,000 to 1,500 per month each). But as of a few weeks ago, the NY consulate now processes all visa applications made in the US, which means that they have to get through an average of about 130 applications per day!
The applications that are sent using priority processing are put to the front of the line, leaving the non-priority applications to wait in line even longer to be processed. As you have a criminal conviction, you may find that you have to wait the normal processing time (currently about 30 working days), plus another 2-3 weeks extra (10-15 working days) while they look into the details surrounding it.