https://en.wikipedia.org/wiki/Callippic_cycle#:~:text=The%20Callippic%20cycle%20(or%20Calippic,the%2019%2Dyear%20Metonic%20cycle.

As we know, the monument is likely in tribute to Robert Carter Cook, was 81 when the Georgia Guidestones were erected. It is similar to how the establishment date for the Guidestones is March 22, the 81st day of the year.
The Callippic Cycle = 81
Callippic = 81
-Ritual = 81 / 81
-In the time of Joe Biden, Mr. 81 Million (President Biden = 81)

Read about Robert C. Cook on the Georgia Guidestones here.

Again, he was 81-years-old when the Georgia Guidestones were unveiled.

Square Root of 81 is 9
Sun = 9 / 18 / 18 / 54
Sun Worship = 54 / 54 / 108 / 162
Callippic = 45 / 54 / 81 / 162
–45, 9th triangular number
-The Guidestones were revealed 18-days before Cook’s birthday (span of 19)

And finally, notice the part about 19. Again, the 19th Tarot Card is the sun card.
Iesus = 19

https://en.wikipedia.org/wiki/Callippic_cycle

And it is a reminder the Guidestones were 19-feet tall, and came down on 19 date numerology, in the time of Cancer, ruled by the moon, with its 19 year cycle, which syncs up with the sun based calendar, the Gregorian, every 19-years.
7/6/2022 = 7+6+2+0+2+2 = 19
6/7 (67, 19th prime)

And the first year of the Callippic was 330 BC, June 28 on the Julian Calendar…
-June 28, BIG date in history, Rosemary’s Baby & beyond

And funny enough this discovery is being made July 11 on the Gregorian calendar
-That’s 13 days later…

And notice the detail about the 47th year of the first Callippic Cycle.
Time = 47
Tropics of the earth 47 degrees apart

The Tropic of Cancer is at 23.5 degrees north, and the Tropic of Capricorn is at 23.5 degrees south. It is kind of like the 235 lunations over the course of 19-years.
-940 lunations in 19 years
-Robert C. Cook, born 9/4 (April 9)

Keep in mind Robert Carter Cook went to George Washington University, and Washington died at age 67, kind of like King George II, who died on the day leaving 67-days in the year, and also like George W. Bush, who turned 76, on July 6, or 6/7, or 7/6, the day the Georgia Guidestones fell down.

In light of the Georgie Guidestones blowing up shortly after their 42nd birthday on March 22, 2022, on July 6, on George W. Bush’s 76th birthday, notice the Callippic Cycle is 76-years, and has a Gematria value of 42.

As we also know, this had a lot to do with the astrological sign of Cancer.

Jesuit = 42
Freemason = 42
Outer Space = 42
*Math = 42
–42 generations to Jesus (Jesuits are Society of Jesus)
-42 generations to Jesus in Matth-ew…

And as for the ‘cancer’ piece…
Cancer, 4th sign
Georgia, 4th state
Cook = 44
Cancer = 44
Georgia = 44
Genocide = 44
Military = 44
500 million = 44
-Georgia Guidestones 19’3″ tall (193, 44th prime)

And for one more points, the Saros and Metonic cycles.

Saros cycle, 223 months (Guidestones established on 22/3)

Metonic cycle, 19-years.