Which day?
The general practice is to use the solar day, 24 hours long, running from noon to noon or midnight to midnight. However, during a solar day, the Earth rotates approximately 361 degrees, not 360 degrees. There was always a faint but nagging doubt in the back of this writer’s mind how this 361 degree cycle could equate to the 360 degree cycle of the solar year. How were these two unequal cycles analogous?
Should we just take this 361/360 disparity on faith, salute and drive on?
The sidereal day, “the interval of time between two successive passages of a star over the meridian” (Nicholas DeVore, Encyclopedia of Astrology, pg 86) or “the time taken by the earth to rotate on its axis relative to the stars” (the Oxford Dictionaries), is the rotation of the earth on its equatorial axis, the midheaven returning to a fixed point in space.
A solar day is 24 hours long; the sidereal day is 23 hours, 56 minutes, and 4.09 seconds in length, or 0.997269676 of a solar day.
The sidereal day is 360 degrees of rotation of the Earth, not the 361 degrees of the solar day. The sidereal day therefore preserves the fractal analogue of a day for a year (for Secondary/Major progressions), or a day for a month (in the case of Tertiaries), in a way the use of the solar day does not.
The effect on Secondary/Major progressions (and Solar Arc directions) if one is using the solar day versus the sidereal day, is that the progressed (directed) positions advance one day further for each year of life. The solar day progressions will be one day ahead for each year of life.
Next I’ll post some examples to illustrate the point.
This thread is to discuss progression techniques, especially the use of the Solar versus Sidereal day. Please DO NOT post any memes or links to videos!
