Cron with a 12-hour issue?

Question

I have a cron job that's managed through plesk. I'm being told that it's being executed twice in a day, once at 5AM and once at 5PM, based on the email that's being received.

Here's the cron line:

0   4   *   *   *   wget http://website.com/script.php

So obviously there's a daylight-savings issue; that's not a problem. But why is it running twice? I thought that the hour specifier was a 24-hour denomination. But it seems to be running at both 4am and 4pm server time.

Please note that I'm managing the cron job though a Plesk web admin panel. I did some googling, but I couldn't find anything about Plesk cron bugs or issues.

What is going on here?

Answer 1

I see 2 possibilities:

1. You're running very-very strange crond
2. There is other cronjob scheduled to 4pm (check global /etc/crontab and crontabs of other users, or any directories with periodical jobs, like /etc/periodic in FreeBSD)

Answer 2

Comment out that line in your cron and see if the job is still getting executed. Then you'll understand that it is scheduled by someone else too.

Answer 3

I don't see anything wrong with your cron job as you describe it. I'd suggest looking at the syslogs of that system to see when cron runs that job. There should be a log entry every time it runs.