I was in front of a computer for 3 days. They did DoK tests for the 4th day, and catching up on any of the modules you may have missed or incorrectly completed.
You're able to test out of the DoK stuff on your first day, though. Do that as quickly as you can and you may not have to show up on Thursday. Friday they'll put a DIAD in your hands for half an hour while they run you through a few mock deliveries. Total driving time at driving school? About 25min.
Focus on your depth of knowledge. Everything else will be learned on-the-job.