The Metonic Cycle, discovered by the ancient Athenian Meton in the 5th century BC, is a period of 19 years, or (235 lunar months) after which the New and Full Moons return to the same days of the year. It was the basis of the ancient Greek calendar and is still used for calculating movable feasts such as Easter.
The year 2020 is five Metonic Cycles from 1925 (19 x 5 = 95; 2020 – 95 = 1925), which means that this year, the Sun and Moon are in a rhythm of repeating the same relationship they had in 1925, the year that Rudolf Steiner crossed over the threshold, from life into being. By March 30, 1925, the Vernal Equinox had already occurred, as well as the first New Moon of the Spring, but the Vernal Full Moon was a rhythm of nine days away, arriving on April 8, 1925 (Wednesday of the Holy Week) with Easter Sunday occurring on April 12.
This rhythm of “five” informs the pentagon, which is the basic structure of the dodecahedron. The dodecahedron is the form Rudolf Steiner gave to the Foundation Stone, which was laid into the Hill at Dornach on September 20 in 1913, and it is the rhythmic form of the five panels of the Foundation Stone Meditation, given during the Christmas Conference 1923/24. As such, a certain completion or fulfillment is achieved when we arrive at the pentagon. 
There are 12 surfaces on a dodecahedron. Twelve Metonic Cycles of 19 years each is 228 years (12 x 19 = 228). If we add 228 years to 1925 (12 Metonic Cycles from Rudolf Steiner’s death), we arrive at the year 2153. This number is somewhat close to the rhythm of precession through the zodiac (2160 years), which is the amount of time it takes for the Earth to wobble 30 degrees on its axis. The Earth exhibits three apparent motions: 1) rotation on its axis, which results in our experience of night and day; 2) orbiting the Sun, which results which our experience of the seasons; and 3) this wobble on its axis, which results in the slow precession of the Vernal Point (as well as a change in which star is the North Star). The wobble occurs at a rate of about 1/72nd of a degree each year. If we imagine 30 degrees for each of 12 signs of the zodiac (30 x 12 = 360), then it follows that the precession of the Vernal Point from one region of the zodiac to the next will take 2160 years (72 x 30 = 2160).
From this, I imagine that, as a sublime event for both the physical and the spiritual worlds, Rudolf Steiner’s death marked a significant moment toward the fulfillment of the Earth’s first leg of precession since the Christ incarnation.
In 2020, the planet Venus will also complete its first five retrograde loops since its rare Transit in 2012, also creating a pentagram around the Earth.
~Mary Stewart Adams
29 March, 2020