In this sample, there's a loop chapter that iterates on the main interview questions, that is, the questions that should be asked each day.
Each iteration represents a day. You'll be able to enter the date in each iteration thus know what questions where answered when.
At the end of each day iteration, we ask the respondent to choose if he wants to complete the interview or move on to the next day.
If he chooses to go to the next day, the loop will continue to the next iteration. Otherwise, the loop will stop and the interview will end.