Originally published August 9, 2017 @ 9:04 pm

The croncal is a clever Perl script that reads entries in your crontab and outputs a schedule, showing the time when cron jobs will run.

This can be useful when planning for server downtime, for example. You may want to know what cron jobs will fail to run and how many times. To download the script:

To use croncal you need to specify three parameters: start time, end time, and the crontab file. The time must be entered in the following format: YYYY-mm-dd HH:MM The following example will list all /var/spool/cron/root cron jobs that will run on the server in the next hour:

Sample output:

Here’s another example: I am using Salt to count all cron jobs in /var/spool/cron on all servers that run during the week:

Sample output:

So the next time your boss says you need to automate more, tell him how many things are happening automatically already :)