Dispatcher Introduction
Figure 1 - The File System setup window (this window is the same for Target setup):
The circumstances you would use the File Name Date Format field include importing CSV files when the file names have the date of the data embedded in it and it’s important to import the data in date order, oldest first. This field will help the system to decode the date in the file name. All the examples seen on the screen were tested with this method. Others would certainly work.