/SLASHPLAY
How to shut down a GMod server when it empties
Type sv_shutdown in the server console and the server shuts down once the last player leaves, without kicking anyone.
sv_shutdown
Schedules the server to shut down as soon as it is empty.
sv_shutdown Examples
sv_shutdown Shut down once everyone has left.
What it does
Lets you stop the server without kicking anyone: it waits for the last player to leave. sv_shutdown_timeout_minutes caps how long it waits.
The game's own description: Sets the server to shutdown next time it's empty
Run it on your server
On a SLASHPLAY server, type it in the Console tab of the server page; the reply shows right under it. A value set there lasts until the server restarts. To keep it, add the line to garrysmod/cfg/server.cfg. New to this? Start a GMod server first.
Your own
GMod server.
From $0.03 an hour, only while it runs. New accounts get 6 free tokens.