Last updated: 13/01/2016
A default Debian installation will log all messages from the cron daemon in the syslog log file ( it can be found in /var/log/syslog ).
The location of the cron log entries can be changed. This means you will have to edit the /etc/rsyslog.conf file.
In the file, you will find the following line:
Uncomment the line (remove the #) and save the rsyslog..conf file.
Next you will have to restart the rsyslog daemon:
service rsyslog restart
After restarting the rsyslog daemon, crontab log entries will appear in the /var/log/cron.log file.