f.lux is a tool that changes the screen color to match the time of day. It's big weakness is that it only has two options for the duration to adjust the color of the display: 20 seconds or 60 minutes.
Are there any windows apps that perform a similar function as f.lux, but allow more flexibility in the duration to change the color of the display? Specifically, I would like something that can change the color more slowly than 60 minutes, just like the real sun.
So far, no answers have been posted, so I have removed the gratis (free of cost) requirement. I would still prefer gratis software, but I am opening this question up to recommendations of commercial software as well.