shutdown

Usage: shutdown [now,cancel,time,die] [comment]
RESTRICTED TO ADMINISTRATORS.

  This command shuts down the server, but with different consequences.  If the
parameter is omitted or is 'now' then the server is immediately halted cleanly
(including games being saved).  If a time is given then a countdown commences
and the server is halted when time is up; "time" is given in seconds (not
minutes).  If 'cancel' is given then the countdown is stopped.  If the
parameter is 'die', the server will be halted immediately without saving
games; this version can be useful for debugging purposes, but users will need
to be warned in advance because the consequences differ from a normal,
announced shutdown.

  You can add an optional comment to this command.  If there is a comment, it
will be displayed to users each time the countdown is updated.  Having a
comment is a useful way to explain the reason for the shutdown and cut down on
the number of questions admins will have to answer about the shutdown.

  Using "announce" may be useful during a coutdown so that users can be
informed of special information, such as how long the shutdown will last.

See ahelp:  announce
See help:   

[Last modified: December 25, 1995 -- Friar]