Problem is that FTP does not support that. There is no "set filetime" command in standard FTP.
There are a couple of extended commands for it that some Servers support. problem is that they work differently and not all server handle them the same.
(Some server expect local time, some expect the time to be GMT and some expect format X and some format Y. )
So it is a mess.
But there is plans to add support for it. But the user might have to configure what extended command to use for it how it should work for the server that they connect to.