My crontab isn't running. After checking the syslog I am getting the following errors: Dec 7 18:57:01 raspberrypi cron[334]: Error: bad username; while reading /etc/cron.d/crontab Dec 7 18:57:01 raspberrypi cron[334]: (*system*crontab) ERROR (Syntax error, this crontab file will be ignored)  I'm trying to schedule a cron task, and it keeps giving me a bad username error... i've tried both: 57 13 * * * pi /home/pi/Desktop/shell.sh  and 57 13 * * * root /home/pi/Desktop/shell.sh  and they're both coming back invalid, what am i missing?