You might want to utilize the file time functions:
[man]filemtime/man
[man]filectime/man
Using one or the other you should be able to get the files modified within the last 7 days.
NOTE Most FTP programs can allow you to keep the local system modified time, which can be greater than 7 days old, while they may have uploaded it today. So these functions may not catch all files as there are ways around it.