The lunation cycle
Traditional; the eight soli-lunar phase types are Dane Rudhyar's
Reading the current sky — the Moon's phase, what is retrograde, the next station and ingress — is as old as astrology itself. The eight-fold division of the soli-lunar cycle into phase types was developed by Dane Rudhyar from the 1940s and given its standard form in The Lunation Cycle (1967).
What it measures
The Sun–Moon elongation that defines the phase, and the sign transits and void-of-course windows of the Moon through a month, with the exact New, First-Quarter, Full and Last-Quarter moments.
Sources
- Dane Rudhyar, The Lunation Cycle (1967)