I don't specify a date. If none is specified, only newer files are
copied, on a file to file basis. The help can be misleading in it's
wording. So the first time you run it, since none of the files exist,
it will copy all the files to the new location. After that it scans
the "source" location (the server) for newer files based on the dates
of any existing copies, and if any particular file is newer , it then
copies that file to the "target" location; then checks the next file in
the "source" location, and so on... If it encounters a completely new
file in the "source" location that does not exist in the "target"
location, it copies it to the target, just as it did when first run.