Answer:
The answer is Islam spread.
June solstice is the time when the Northern Hemisphere is
tipped most specifically toward the Sun and gets the most direct daylight. It
happens around June 21 (also called summer solstice) on the day where the Sun
takes after its longest and most elevated way through the Northern Hemisphere
sky and its shortest way through the Southern Hemisphere sky.
It was the most accurate calendar of the time!
It is formed by plate tectonics
