<i>> the arcane syntax</i><p>Arcane, seriously? What kind of syntax would be modern and clear in your opinion? YAML? JSON? XML probably, with a nice 150-page <i>XTBJSPCOSDF (Extensible Time-Based Job Scheduling for POSIX-Compatible Operating Systems Description Framework)</i> spec? ;)<p>Personally, I think this is pretty straightforward:<p><pre><code> #minute hour mday month wday command
30 1 * * * /bin/sh /etc/daily
30 3 * * 6 /bin/sh /etc/weekly
30 5 1 * * /bin/sh /etc/monthly</code></pre>
I'd dig something going in the opposite direction! Especially packed in a shell script, e.g. `cronglish "echo testing" every half hour >> ~/.crontab`
OK, so I gave it this:<p><pre><code> 8-59/30 * * * * do_something
</code></pre>
It replied:<p><pre><code> The command do_something will execute
the 8th through 59/30th minutes of
every hour every day.
</code></pre>
That's a pretty poor description of something that will run at 8 and 38 minutes past the hour, every hour of every day.<p>Not impressed - seems overly simplistic.
I built the opposite version of this, convert plain English to cron commands: <a href="http://thomseddon.github.io/cronstring" rel="nofollow">http://thomseddon.github.io/cronstring</a>
You can also use DuckDuckGo to do this: <a href="https://duckduckgo.com/?q=cron+0+0+*+*+*+some_report.sh&t=lm" rel="nofollow">https://duckduckgo.com/?q=cron+0+0+*+*+*+some_report.sh&t=lm</a>
Looks like they're the chaps behind <a href="https://deadmanssnitch.com" rel="nofollow">https://deadmanssnitch.com</a> which looks like a simple and useful service.
For visualizing a large quantity of crons, I'd recommend something akin to <a href="https://github.com/federatedmedia/cronviz" rel="nofollow">https://github.com/federatedmedia/cronviz</a> which will graphically show when jobs are scheduled to run.
@reboot cd ~/bin/some_daemon<p>is not a very good example. It will launch a shell which will change to the specified directory and then terminate. (It might produce an error message if the directory doesn't exist.)
This is nice.<p>I also turn to <a href="http://cronwtf.github.io" rel="nofollow">http://cronwtf.github.io</a> when I need to sanity-check my crontab, which is a little more verbose and includes JSSpec tests.
Also see crontab2english:
<a href="http://interglacial.com/pub/crontab2english.html" rel="nofollow">http://interglacial.com/pub/crontab2english.html</a>
I've been using <a href="http://cronwtf.github.io/" rel="nofollow">http://cronwtf.github.io/</a> for years to double-check cron expressions.