try
    {
    // make the destination root the current working directory
    Environment.CurrentDirectory = target.FullName ;
    // enumerate over the files in the source directory
    foreach ( FileInfo fi in source.EnumerateFiles() )
    {
    // parse a datetime out of the file name
    DateTime? timestamp = fi.TimestampFromName() ;

    // construct the relative path of the archive subdirectory
    // and ensure that it exists
    string relativeSubdir = timestamp.Value.ToString("yyMM\yyMMdd") ;
    DirectoryInfo subdir = target.CreateSubdirectory( relativeSubdir ) ;

    // build a relative path to the file's desired location
    // and move it there.
    string destination = Path.Combine( relativePath , fi.Name ) ;
    fi.MoveTo( destination ) ;