To learn about the retrograde planets and three stages of retrograde motion, read this article: About the Retrograde Planets
You will find all the dates for all the retrograde periods of personal planets in the interval from 1900 to 2050 on these pages:
To learn about the planetary hours and days, read this article: Planetary Hours and Days
To define them for almost any location on the Earth, use the Planetary Hours Calculator
The home page of Lunarium displays the declination
This idea is based on the declination of planets. So you might want to read the declinations article first.
And then there is another article, right on the subject: Out-Of-Bounds Planets
For a practical test of this idea, use the Out-Of-Bounds Calculator.
© 2021 Alexander Kolesnikov