I wrote this little script to help me keep on track with my reading. I needed to read 2 chapters of each of 3 different books today, and I wanted to assign one hour to each chapter, but in order to keep on track, I wanted to see what page I should be on at each moment, so that's why I wrote this script.
It's in python. Just tell it the amount of time or the time you want to finish (e.g. '1hour' or '2pm', anything that is supported by the gnu date `-d` argument), the page you're starting on, and the page you're finishing on, and it will continuously tell you where you should be in your reading.
https://github.com/mica5/reading-progress