Debug crontab error log

1. Setup crontab
```
$ crontab -e
59 23 * * * /home/john/bin/backup.sh
```

2. View log running
```
$ tail /var/log/cron
Oct  8 22:00:00 dev-db crond[18340]: (root) CMD (/bin/sh /home/root/bin/system_check &)
Oct  8 23:00:00 dev-db crond[20348]: (oracle) CMD (/bin/sh /home/oracle/bin/cleanup.sh &)
Oct  8 23:59:00 dev-db crond[20399]: (john) CMD (/bin/sh /home/john/bin/backup.sh &)
```

3. Debug log error
```
$ crontab -e
59 23 * * * /home/john/bin/backup.sh > /home/john/logs/backup.log 2>&1
```
Note:
- > /home/john/logs/backup.log indicates that the standard output of the backup.sh script will be redirected to the backup.log file.
- 2>&1 indicates that the standard error (2>) is redirected to the same file descriptor that is pointed by standard output (&1).
- So, both standard output and error will be redirected to /home/john/logs/backup.log