The GetFileTime method uses the HEAD command to retrieve
header information about the file without downloading the contents
of the file itself. This requires that the server support at least
version 1.0 of the protocol standard, or an error will be returned.
The server may not return a modification time for some resources.
If the request to the server was successful and the file exists, but
the server does not return a modification time, the method will
return an empty string.
When a request is made to the server for information about the
file, the control will attempt to keep the connection alive, even if
the KeepAlive property has not been set to True. This allows
an application to request the modification time and then download the
file without having to write additional code to re-establish the
connection. However, it is possible that the attempt to keep the
connection open will fail. In that case, an error will be returned
and the session will no longer be valid. If this happens, the method
may still return a valid date and time. To determine if an error
occurred, check the value of the LastError property.
The Localize property will determine if the returned file
time is adjusted for the local timezone.