ftp 的規範並沒有定義保留時間這一部分。而相對於目的地的系統，當然是以檔案複製完成的時間為建立時間。

所以一般我們在設計軟體的時候，首先在讀取檔案的時候先紀錄檔案在原始位置的時間，等傳送完成後，再修改其時間，以下是一段 C++ 的例子：

 // 取得檔案資訊之後，開始下載
   if (!DownloadFile(localFileArray[0].m_szFullName, strLocalName, bResume, localFileArray[0].m_size, localFileArray[0].m_mtime))
   {
    break;
   }

//下載函式
BOOL CDownloadThread::DownloadFile(LPCTSTR lpszRemoteFile, LPCTSTR lpszLocalFile, BOOL bResume, __int64 dwLength, CTime &lastModificationTime)
{
 
//........  
//略...
//......

  if (m_bPreserveRemoteTimeStamp) //判斷是否要保留來源的時間
 {
  try
  {
   CFileStatus status;

   status.m_attribute = 0x00;
   status.m_mtime = lastModificationTime;
   status.m_ctime = lastModificationTime;
   status.m_atime = lastModificationTime;
   CFile::SetStatus(lpszLocalFile, status);
  }
  // just ignore any errors
  catch (CFileException *e)
  {  
   e->Delete();
   //略...
  }
  catch (...)
  {
    //略...
  }
 }
 return TRUE;
}

以 RunFTP 為例，使用者就可以自己決定傳遞後動作與時間戳記：

※以下為範例程式，請自行服用，風險自負...

'Win API
GetFileTime
SetFileTime

'API宣告
Private Declare Function GetFileTime Lib "kernel32" Alias "GetFileTime" (ByVal hFile As Long, lpCreationTime As FILETIME, lpLastAccessTime As FILETIME, lpLastWriteTime As FILETIME) As Long

Private Declare Function SetFileTime Lib "kernel32" Alias "SetFileTime" (ByVal hFile As Long, lpCreationTime As FILETIME, lpLastAccessTime As FILETIME, lpLastWriteTime As FILETIME) As Long


'函數實作範例：

' Return True if there is an error.
Private Function GetFileTimes(ByVal file_name As String, _
    ByRef creation_date As Date, ByRef access_date As Date, _
    ByRef modified_date As Date, ByVal local_time As _
    Boolean) As Boolean

Dim file_handle As Long
Dim creation_filetime As FILETIME
Dim access_filetime As FILETIME
Dim modified_filetime As FILETIME
Dim file_time As FILETIME

    ' Assume something will fail.
    GetFileTimes = True

    ' Open the file.
    file_handle = CreateFile(file_name, GENERIC_READ, _
        FILE_SHARE_READ Or FILE_SHARE_WRITE, _
        0&, OPEN_EXISTING, 0&, 0&)
    If file_handle = 0 Then Exit Function

    ' Get the times.
    If GetFileTime(file_handle, creation_filetime, _
        access_filetime, modified_filetime) = 0 Then
        CloseHandle file_handle
        Exit Function
    End If

    ' Close the file.
    If CloseHandle(file_handle) = 0 Then Exit Function

    ' See if we should convert to the local
    ' file system time.
    If local_time Then
        ' Convert to local file system time.
        FileTimeToLocalFileTime creation_filetime, file_time
        creation_filetime = file_time

        FileTimeToLocalFileTime access_filetime, file_time
        access_filetime = file_time

        FileTimeToLocalFileTime modified_filetime, file_time
        modified_filetime = file_time
    End If

    ' Convert into dates.
    creation_date = FileTimeToDate(creation_filetime)
    access_date = FileTimeToDate(access_filetime)
    modified_date = FileTimeToDate(modified_filetime)

    GetFileTimes = False
End Function

' Return True if there is an error.
Private Function SetFileTimes(ByVal file_name As String, _
    ByVal creation_date As Date, ByVal access_date As Date, _
    ByVal modified_date As Date, ByVal local_times As _
    Boolean) As Boolean
Dim file_handle As Long
Dim creation_filetime As FILETIME
Dim access_filetime As FILETIME
Dim modified_filetime As FILETIME
Dim file_time As FILETIME

    ' Assume something will fail.
    SetFileTimes = True

    ' Convert the dates into FILETIMEs.
    creation_filetime = DateToFileTime(creation_date)
    access_filetime = DateToFileTime(access_date)
    modified_filetime = DateToFileTime(modified_date)

    ' Convert the file times into system file times.
    If local_times Then
        LocalFileTimeToFileTime creation_filetime, file_time
        creation_filetime = file_time

        LocalFileTimeToFileTime access_filetime, file_time
        access_filetime = file_time

        LocalFileTimeToFileTime modified_filetime, file_time
        modified_filetime = file_time
    End If

    ' Open the file.
    file_handle = CreateFile(file_name, GENERIC_READ, _
        FILE_SHARE_READ Or FILE_SHARE_WRITE, _
        0&, OPEN_EXISTING, 0&, 0&)
    If file_handle = 0 Then Exit Function

'creation_date = FileTimeToDate(creation_filetime)

    ' Set the times.
    If SetFileTime(file_handle, creation_filetime, _
        access_filetime, modified_filetime) = 0 Then
        CloseHandle file_handle
        Exit Function
    End If

    ' Close the file.
    If CloseHandle(file_handle) = 0 Then Exit Function

    SetFileTimes = False
End Function

沒問題啦，我們是自己的主機和專線，頂多網站慢一點而已