Night Shift doesn't cut it.
Night Shift warms the screen a little. It does not take the blue out. The control that actually does is buried three levels down, in System Settings › Accessibility › Display › Color Filters, turned on and pushed all the way to red.
That works. What does not work is remembering to do it every evening and undo it every morning. Doing it by hand got old fast. So this is a small app that does it for you.
It reads sunset and sunrise for wherever you are, flips the filter on when the sun goes down, and off when it comes back up. It re-checks on a timer and whenever the Mac wakes, so sleep, daylight saving and the seasons never leave it stuck on at noon.
It also leaves your setup alone. Whatever filter type you picked stays picked, only the switch and the strength move.
The first time you open it, hold Control, click the app, and choose Open. Your Mac shows a warning for small apps like this one that it has not checked over. Choose Open once more and that is the last you will see of it.