cron job every 5 hours

[Olivier Nicole]

>     Something like:
> 
>     minute */5 * * * root path/to/scriptname
> 
>     will do the trick.
> 
>     Substitute the * in */5 for your desired start time (* being 0).
> 
> -Garrett
> 
> PS crond won't do 5 hours and every x number of minutes per job (5 hours 
> + x mins from end to start), just a flat amount of time (5 hours apart 
> from start to start). If you need that type of 'precision', at will 
> solve that like Olivier said if you place it at the end of the command.

I am afraid not.

*/5 means on every hours that is a multiple of 5, not every five
 hours. So it will run every day at hour 0, 5, 10, 15 and 20. Between
 hour 20 one day and hour 0 the next day there is only 4 hours, not
 the "every 5 hours" requested.

Just to confirm that I launched a cron job yesterday:

23 */5 * * * /home/java/on/crontest

It ran at 15:23, 20:23 and today at 0:23 and 5:23 and so on:

Date: Wed, 18 Jul 2007 05:23:00 +0700 (ICT)
From: Olivier Nicole <on at cs.ait.ac.th>
To: on at banyan.cs.ait.ac.th
Subject: test crontab 5 hours
X-Virus-Scanned: on CSIM by amavisd-milter (http://www.amavis.org/)

This is a test for crontab


Only way to run a job every 5 hours is with at(1).

Best regards,

Olivier