Tag Archives: seasons

February 19, 2018 Winter into Spring

金山巨石群 冬期120日間終了の光

Kanayama Megaliths 120 Days of Winter Ends 2018 21519

This is our excerpt from the blog posted by the Kanayama Megaliths Research Center at  http://blog.livedoor.jp/kanayama_tour-kanayamamegaliths/archives/1070157722.html on 2018.02.22. 

The face of the Sekimen stone in Iwaya-Iwakage is lit by a spotlight for five days from February 15 to 19. February 19 marks the end of the 120-day winter season. (The exact number of days was 119.) The 120 days of winter can be divided into the 60 days of Early Winter ending on the Winter Solstice and the 60 days of Late Winter following the Solstice.


The Kanayama blogsite has posted two photos taken on 2018.02.19 at 13:23 and 13:33. Note how well the lower edge of the spotlight matches the edge of the Sekimen. Comparison of the two photos shows that the solar altitude has decreased during the ten minutes lapse, causing the spotlight to move higher “up” the stone face. The spotlight of 2/19 matches that of 10/23, because the sun’s altitude is the same on these two days.


Here is a view of the beam of light entering from the crevice above. Three megaliths form the crevice and shape the sunbeam in exactly the right way.





Why are the Vedic and Jomon Calendars Identical?


The Hindu calendar which comes from the Vedas of 1200 BCE has six seasons called ritu.  The seasons and their dates are listed here.

Vasant     Spring         2/18 – 4/19

Grishma  Summer     4/19 – 6/21

Varsha     Monsoon     6/21 – 8/22

Sharad     Autumn       8/22 – 10/23

Hemant   Prewinter   10/23 – 12/21

Shishir     Winter        12/21 – 2/18

Six-season chartThe Jomon calendar of the Kanayama Megaliths has these six seasons.

Spring                           2/19 – 4/22

Early Summer            4/22 – 6/21

Late Summer              6/21 – 8/20

Autumn                        8/20 – 10/23

Early Winter               10/23 – 12/22

Late Winter                 12/22 – 2/19

The dates 2/19, 4/22, 8/20, and 10/23 are astronomical cross-quarter days. Compare the corresponding dates of the two calendars and we find that they differ only by 0, 1, 2, or 3 days. The summer solstice date is exactly right for India and for Japan. The winter solstice dates are 12/21 for India and 12/22 for Japan, so they do agree. The spring and autumn equinoxes are the middle date of both the Vedic and the Jomon calendars.

How the Jomon determined the seasonal dates.  You may be wondering what is the rule for the dates of 2/19, 4/22, 8/20, and 10/23 in the Jomon calendar. These are the dates when the sun’s altitude at noon is half-way between those of the winter solstice and the equinoxes for dates 10/23 and 2/19; half-way between those of the summer solstice and the equinoxes for dates 4/22 and 8/20. These dates are called yontobun in Japanese. It means dividing the zone of the sky between the highest and lowest altitudes into four parts.

How did the Vedic calendar determine the seasonal dates? Of the Hindu calendar it can be said:  Seasons follow the sun; months follow the moon; days follow both sun and moon. The seasonal dates of the Vedas roughly correspond to seasonal weather patterns, as can be seen from Monsoon as the late summer season. But why these exact dates? The calendar of the solar year is important for scheduling religious festivals. The ancient people of India were excellent astronomers who carefully studied the skies. They were familiar with the planets and the stars. So they must have had a good reason for selecting these particular dates. What was their reason?

Discussion.  From Internet articles about the Hindu religious calendar, we learned that government astronomers studied the position of the sun as it rose against the distant stars in order to determine the seasonal dates. This is not unlike the Jomon astronomers who used the position of the sun in the daytime sky to determine their seasonal dates. Once the Jomon people had set up the working megalithic observatory at Kanayama, they could simply watch the sunlight patterns to calibrate their calendar. They constantly monitored and updated their solar calendar so that it remained accurate to within one day.

While the dates of the six seasons of the Vedic and Jomon calendars agree closely, it is only a matter of time before the Vedic dates will drift slowly away, the effect of earth’s axial precession relative to the distant stars. The Jomon calendar may still be keeping good time, since it is watching the sun relative to Earth.