lftp ?

Description: Sophisticated command-line FTP/HTTP client programs
Lftp is a file retrieving tool that supports FTP, HTTP, FISH, SFTP, HTTPS
and FTPS protocols under both IPv4 and IPv6. Lftp has an amazing set of
features, while preserving its interface as simple and easy as possible.
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The main two advantages over other ftp clients are reliability and ability
to perform tasks in background. It will reconnect and reget the file being
transferred if the connection broke. You can start a transfer in background
and continue browsing on the ftp site. It does this all in one process. When
you have started background jobs and feel you are done, you can just exit
lftp and it automatically moves to nohup mode and completes the transfers.
It has also such nice features as reput and mirror. It can also download a
file as soon as possible by using several connections at the same time.
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Lftp can also be scriptable, it can be used to mirror sites, it lets you
copy files among remote servers (even between FTP and HTTP). It has an
extensive online help. It supports bookmarks, and connecting to several
ftp/http sites at the same time.

Et extrait du man :

repeat [delay] [command]

Repeat the command. Between the commands a delay inserted, by default 1 second. Example:
repeat at tomorrow -- mirror
repeat 1d mirror