Consider the Cronslave

As a nerdy, working-class kid who grew up in the 1990s, knowing what time it actually was was a luxury I rarely had access to before I was 12 or so and my parents finally got an Internet connection with its attendant link to the Network Time Protocol. If you had told me I could have not just a watch but an entire machine that

1. Never lost the time,
2. Did what I wanted, how I wanted it, and
3. Could be programmed to do what I want, how I want it on a schedule,

I would have had to substantially revise my Christmas wishlist.

Such technology is ubiquitous today, of course. Many computer programs called ‘daemons’ seek rent on your precious electrons in exchange for granting you unique powers and abilities, and this was both one of the earliest and one of the most powerful such abilities to emerge. The best-known of these programs is called cron, and individual tasks like “email me every night at 3 AM” is called a “cronjob”. Many other programs do more or less the same thing, with some enhancements here or there - I particularly like what systemd’s timers can give you - but the terms “cron”, “cronjob” and “crontab” escaped containment long ago and are now used to refer to this general class of daemonic entities.

A cronslave, then, is simply a personal computer you keep running more or less 24/7 for the primary purpose of running cronjobs. It is a term which springs Athena-like out of the head of childhood me. There are many, many services which will host cronjobs for you for free, but cron itself is a mercifully slim program, and a $50 Raspberry Pi will happily run dozens or even hundreds of cronjobs for you in parallel for years to come.

The possibilities of what you might want to actually do with your cronslave are limited only by your imagination. Shell scripting used to be a bottleneck, but LLMs turn out to be a perfect use case for bashing (heh) out 50-100 line scripts complete with logging and error handling. Want phone notifications? Put a curl to ntfy.sh, subscribe on your phone, and bam - updates every hour on the hour. Want to archive a website daily? Nothing’s stopping you from git scraping the site, and maybe even running it through a pandoc-and-perl pipeline to clean it up into nice, easy to use Markdown. How about automating a backup with rsync or its less civilized cousin rclone?

Consider setting up a cronslave. It’s easier than you think, and you would be surprised how many things become easier when you have a tiny always-on box sipping 50 cents of electricity a year in exchange for mastery of time. For what it’s worth, I run Tiny Core Linux and use the BusyBox cron implementation, but I’m a tryhard. Good old Debian will do everything you want for a fraction of the setup time.