Tente isto:
find /folder/*.* -mtime +14 -exec rm -Rf {} \;
find:
search for files in a directory hierarchy
-mtime n:
File's data was last modified n*24 hours ago.
-exec command ;
Execute command;
-exec command {} +
This variant of the -exec action runs the specified command on the selected files
rm:
remove files or directories
-r, -R, --recursive
remove directories and their contents recursively
-f, --force
ignore nonexistent files, never prompt
{}
Remove (unlink) the FILE(s).
Este script procura por arquivos e remove recursivamente arquivos / pastas com 14 dias de modificação