Minecraft wiki entry for Mac_Scripting_Tutorial, associated text: To tell cron to run this script nightly whether or not a user is logged on, you'll need to edit the system crontab file, which is located at /etc/crontab (though on OS X 10.6.x, the file might not exist—if that's the case, then you can create it yourself). Open the file for editing and paste in the following line: