If you haven't heard of run-at-time in Emacs, now you know. Also included is a demo of using run-at-time to send yourself a future notification in macOS.
http://yummymelon.com/devnull/scheduling-future-tasks-in-emacs.html

#Emacs

Scheduling Future Tasks in Emacs

Back when I had to run a lot of long-running simulations on Unix systems, I became an ardent user of the at command, which lets one schedule a program to run at a future date. I also used at...

@kickingvegas Off topic but would be nice if you could add https to your website. :)
@paniash Not willing until I find hosting that is cheaper than what I've currently got.
@kickingvegas Usually hosting providers these days provide https for free (via Let's Encrypt). I use statichost.eu for my website needs and it's free for a personal website and I'm very happy with it.