Dedicated Server Console Commands

[Orthopaktis]

Is there any way to send an in-game message as "server" using the console of a dedicated server? I would like to set up an automated message that posts an hour before regular restarts to warn players, but I'm unaware of what the command (if any) is to send messages.

Bear in mind that my hosting service can automate the command, all I'l asking for is if there is one and what is it. I haven't been able to find a list of server commands anywhere.