Finding which cron jobs are scheduled to run at some future date/time X

After a quick glance at the source (in Debian squeeze, which I think is the same version), it does look like entries within a given file and with the same times are executed in order. For this purpose, @daily and 0 0 * * * are identical (in fact @daily is identical to 0 0 * * * in this cron).

I would not rely on this across the board. It's possible that one day someone will decide that cron should run jobs in parallel, to take advantage of these 32-core CPUs that have 31 cores running idle. This might be done when implementing this 20-year old todo item encountered in the cron source:

All of these should be flagged and load-limited; i.e., instead of @hourly meaning "0 * * * *" it should mean "close to the front of every hour but not 'til the system load is low". (…) (vix, jan90)

It's very easy to write @daily job1; job2 here. If it's important that the jobs execute in order, make it a direct consequence of what you write.

Additionally, making the order explicit removes the risk that a future administrator will reorder the lines thinking that it won't matter.

I can't give you a specific answer, but here is how i would go about troubleshooting this:

1. Try more combinations to find another working expression. How about: */2 * * * * (every other minute), or * */2 * * * (every minute, every other hour). It would be interesting to establish that any relative expression works while fixed expressions do not.

2. When you save, do you see the confirmation message "New crontab installed?" (or something similar)

3. Can you do a crontab -l to see your message?

4. Is this a user crontab or system crontab?

5. Do you see messages in syslog? If you add a second, * * * * * cron you should see that every minute, and if you add the every-other-minute variant, can you see in syslog just the more frequent job?

6. Can you configure a working at command?

7. When you have this figured out, I would suggest using a service I built, https://cronitor.io to keep an eye on your important jobs. It's free for a developer to monitor one job and there are paid plans for business use. I had become too much of an expert cron debugger over the years and knew that if I needed a solution to monitor my important jobs other people probably did too.

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Cron uses the same system timezone for kicking-off jobs, so I would try just resetting that:

1. Set your timezone again, just to be thorough: on Red Hat use redhat-config-date

2. Restart the cron daemon. I think on your OS version: /etc/init.d/crond restart