This command displays information on how long the server has been 'up'. Other information may also be displayed. This is a request to place this idle link as an active link. If 'text' is not present, then he is back again. The given text should be stored in your server to give a hint to the users doing a private message to an person who is away.
Time indicates, when the command was issued.
This is a channel message. The 'text' should be delivered to all users on this channel, and to all hosts who are a downstream for a user in this channel. Otherwise, the server can render the 'text' in whatever manner it desires. The 'host' is reachable via the host sending the command, and can be reached in 'time' seconds. The 'connhost' is the server which is the connection point for 'host' into the network.