=== Format ===
__**Note**:__ When creating crons, you will need to specify the FULL path to a command. \\
Eg. On the command-line you may type:
<sxh bash>
holland bk
</sxh>
This is because bash shells introduced the $PATH environment variable:
<sxh bash>
# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
</sxh>
The shell will then search the environment variables from right to left until it finds the appropriate path. This allows you to type the command and options rather than the full path to the init script. \\
Cron DOES NOT have this functionality. You will need to type the full path:
<sxh bash>
# which holland
/usr/sbin/holland
</sxh>
The cron would then look like:
<sxh bash>
00 2 * * * /usr/sbin/holland -q bk
</sxh>
\\
\\
=== Format ===
To view the format of crontabs you can read the file /etc/crontab
<sxh bash>
minute   hour   day   month   dayofweek   command
  *        *     *      *       *
</sxh>
The diagram below shows a little more detail into the parameters of each column
<sxh bash>
*     *     *   *    *        command to be executed
-     -     -   -    -
|     |     |   |    |
|     |     |   |    +----- day of week (0 - 6) (Sunday=0)
|     |     |   +------- month (1 - 12)
|     |     +--------- day of        month (1 - 31)
|     +----------- hour (0 - 23)
+------------- min (0 - 59)
</sxh>
 

**Viewing configured crontabs**

You can use the following command to see the configured cronjobs on the server:
<sxh bash>
crontab -e
</sxh>
 

**Example Crontabs**
<sxh bash>
min   hour   day   month   dayofweek   [command]
30    0      1    1,6,12     *    [0:30 Hrs  on 1st of Jan, June & Dec]
10    4      1      *        *     [1st of every month @ 4:10]
</sxh>