Minecraft wiki entry for Mac_Scripting_Tutorial, associated text: Make sure to substitute in the path to the Tectonicus script. The first two characters are the minute and hour that cron will execute the script in 24-hour notation, so the line as it is above will run the script every night at 01:00. To change it to 03:30, you'd replace the "0" with "30" and the "1" with "3".