Ideally, I want a scheduled gradual sunset over one hour or so. I want it to work so that my eyes and brain have time to adjust, and I don't even notice the change, like a slow sunset. I don't see how I could do this with a cronjob and f.lux. Am I missing something?

For this reason, I actually used a patched version of Redshift back when I was on a Linux desktop. Now I'm on a Mac. I used to run f.lux, until Night Shift came out with the superior scheduling options.

I do believe in the "amount of blue-green light" argument from the f.lux guys, and would like to see a way to configure macOS to almost completely eliminate blue light, like f.lux does. If f.lux were to introduce a simple schedule option a'la Night Shift, I might switch back.

Or use the alternative tool that he's talking about that supports his use case directly.

That will probably not work in the summer. f.lux won't turn on its effect until the sunset at midnight for example, even if you start it at 9pm (planning to go to sleep at 10pm).

macOS supports cron, but doesn't have a command line flux tool.