In the main menu Server > Main settings > Server dialog, the VisualCron server status can be set to "On" or "Off". The server status is indicated and/or managed by any connected client by the "Server [On]" or "Server [Off]" text in the main menu Server option.
The status "Server [Off]" means that the service is running but the server doesn't execute the defined Jobs or Tasks, and the NextRun field for any active Job will show the "Server off" text. Switching to "Server[Off]" may be used as an emergency stop for the current Job/Task execution.
Once you have changed the server status, the status will be saved and VisualCron will use that status the next time the server computer is started.