Category Archives: Astronomy

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.







Winter Solstice Sunlight at Simulator and the Split Boulder

We conclude our three-part series reporting on the Kanayama Megaliths blog about the winter solstice. In the early afternoon of the solstice, the simulator is displaying perfectly the path of the sunlight. The spot of light strikes the observation panel precisely, which glows as if lit from within.

The winter sunset is also observable near the Senkoku-ishi. There is a pair of megaliths that clearly has been naturally divided in two. First take a look at the set-up. The sun is already striking the pair.



If you stand in back of the gap at sunset, you can gaze on this striking  sight!


The reason that all these winter observations are possible in the mountainous terrain of the Kanayama Megaliths is that the megalith sites are intelligently located so as to take advantage of the astronomical geometry, i.e., the line to the winter solstice setting sun. Moreover, isn’t this a magnificent view of the place where the sun goes to rest in winter?





Winter Solstice 2017


Kanayama Megaliths in December by S. Tokuda

Winter weather has arrived in the mountains of Kanayama. The solstice is coming soon to the megaliths. It will arrive on Friday, December 22, 2017 at 1:28 am. Unless you live in the same time zone, it will probably arrive for you on Thursday the 21st. See the dates and times below.

EarthSky has a posted information about the winter solstice of 2017. Here are some excerpts telling us that the four quarters of the year vary in length from 89 to 94 days. There is an exciting graphic as well on the site.

The 2017 December solstice will come on the December 21 at 16:28 UTC. That’s 10:28 a.m. on December 21, for those in the central time zone in North America. It’s when the sun reaches its southernmost point for the year. This solstice marks the beginning of the winter season in the Northern Hemisphere, and the start of the summer season in the Southern Hemisphere. And, no matter where you are on Earth, it marks the beginning of your shortest season.

By season, we mean the time between a solstice and an equinox, or vice versa. The upcoming season – between the December solstice and March equinox – is a touch shy of 89 days.

Contrast the number of days of the upcoming season with that of the longest season, a Northern Hemisphere summer or Southern Hemisphere winter. The longest season as measured from the June solstice to the September equinox lasts 93.65 days.

Why is the upcoming season nearly 5 days shorter? Every year in early January, the Earth swings closest to the sun for the year. Because Earth is nearest the sun at this time, Earth moves most swiftly in its orbit. That’s why a Northern Hemisphere winter or Southern Hemisphere summer is the shortest of the four seasons.

On the other hand, in early July, Earth is farthest from the sun and moving most slowly in its orbit.

Lengths of the astronomical seasons:

December solstice to March equinox: 88.99 days
March equinox to June solstice: 92.76 days
June solstice to September equinox: 93.65 days
September equinox to December solstice: 89.84 days

For those in various time zones, here are some astronomical dates and times of the winter solstice.

Fri 1:28 am     Tokyo
Thu 9:58 pm    New Delhi
Thu 7:28 pm    Moscow
Thu 4:28 pm    London
Thu 11:28 am    New York
Thu 8:28 am     Los Angeles
Thu 6:28 am     Honolulu

For those who have accessibility issues, we thank a reader for suggesting this site

For Kanayama megalith visitors, there will be a hike up Higashinoyama on the morning of the winter solstice.

December 22 – December 24
Dec 22 at 7:30 AM to Dec 24 at 4:20 PM UTC+09
See the link for details.

A Visit to Asadori Myoujin

DSC04552 hokora & stones

October 16, 2017.  This is the report of our visit to the Asadori Myoujin shrine. We have reported that a Himukae winter festival takes place here on winter solstice mornings to welcome the sun. Our specific purpose was to study the layout of the stones which are said to mark directions to sunrises on solstices and equinoxes.

We visited Asadori Myoujin in the rain. The site is raised slightly above the surrounding plain. We parked in the lot with a sugi grove to the southeast. We turned to face the torii, and we could see that the path led straight to a second torii on the grounds. This would be the path of the sunlight on winter solstice morning. The azimuth angle was verified by our analog and digital compasses.

DSC04541DSC04556 copy


We pray at a small hokura in front of a mound. See photo at top. Directly in front of us is the sun-stone draped in shimenawa. Beyond it we see the top of another stone. Here is a close-up so that you can see the stone behind the shimenawa sun-stone.

DSC04552 hokora & stones copy

Distance measurements were taken with a laser measure. The distances found are:  from second torii to hokura base, 5.1m; to the sun stone,  11.0m; and to the winter solstice stone, 19.0m.

It has been reported that there are four or five stones lined up in a row, the one furthest west of the winter solstice stone would be the summer solstice stone. We are unable to see the other stones due to the topography and the growth of plants, plus the area behind the hokura is cordoned off with bamboo. We would have liked to take measurements of the distances between the stones. Unfortunately, we could not do it. So we will have to return another time when there is less vegetation and we can see the other stones.

This is the alignment on winter solstice morning: sunlight streams through the first torii, the second torii, the hokura, the sun-stone, and the winter solstice stone. Here is the view looking from the inner torii to the place where the winter solstice sun will rise. 


We noticed that the rising winter solstice sun would be blocked by the grove of tall sugi on the other side of the parking lot, in the background of the above photo. Perhaps the winter Himukae festival takes place after the sun has cleared the trees.






The Revival of the Sun’s Power on Winter Solstice Morning: Asadori Myoujin


The Asadori Myoujin is a shrine in the Mino area of Gifu-ken that goes back to very ancient times. It observes a solar calendar in which the year begins on winter solstice day, when the sun in the northern hemisphere is as far south as it gets and begins its annual journey northward again. It is a cause for celebrating the return of the sun.

We found a description of the festival on a blog on musublog.  Our free translation below helps us to understand a little better the people’s reverence for the Hi no Kami, Kami of the Sun.


The Winter Solstice Matsuri of Asadori Myoujin (Gifu-ken Ibigawa-machi)

There is an unusual festival reminiscent of an ancient winter solstice ceremony from the Ibukiyama and Ikeda mountains nestling in the Yoro Ranges, along the Ibigawa River in the north.

朝鳥明神 Asadori (Asatori) Myoujin was founded as an old shrine 古社, listed in the national history book about 1500 years ago, from around the 4th century. It is the oldest shrine in the prefecture in which an ancient ritual remains. This shrine became the base of the making of the country of Mino-no-kuni.

The shrine is set in a luxuriantly forested sacred mountain, and even now has the appearance of ancient shrine creation.

The white wooden torii is called Shime Torii, a gate where the 朝鳥明神 Asatori Myoujin enshrines 日の神, the Kami of the Sun, on winter solstice morning as the sun shines through the gate that determines the azimuth of the sun. This festival is held for 明神さま Myoujin-sama every year on the early morning of the winter solstice.

Originally there was no shrine, and an Iwasaka (rock border) is enshrined as a divine body in the hilly area behind it. Right behind that is the 朝烏古墳群 Asadori Burial Mound Group; it is the center of the worship of the Hi no Kami (Kami of Sun) of the ancestors.

This festival (日迎えの神事, Himukae ceremony) for greeting the revival of the power of the sun at sunrise  began before the founding of Japan. On the day of the festival, local members will ignite fires from early dawn, give a norito and wait for the winter solstice sun to rise.

Before one’s eyes, spreading from the direction of the Noubi Plain (direction of Seto), the sun shows its face. The beginning light passes through the torii directly to the goshintai in the rear, and the center of the iwasaka’s remarkably huge Sun Stone is illuminated.

This ends our report on this blog. We are hopeful of visiting the shrine and bringing you photos of the torii and the sun-stones.





May 22 and 23 at Senkoku-ishi

May 22, the second day of the dashed spotlight.

Today, the dashed light is clearer than it was yesterday. The bottom dash is slight, but it hits the corner. From tomorrow the width of this light becomes thicker and stronger; the light can be regarded as a dotted line until about the fifth day, the 25th of May.




May 23, the third day of the dashed spotlight.

The observation is impressive today. A dash starts appearing one by one from the top. It takes about three minutes for up to six dashes to appear (see closeup below).


この三角状の石面の凹凸も計算されているのでしょうか!? 完全に遊んでますね。

Is the roughness of this triangular stone surface deliberate? It plays perfectly!


The dashed lights move downward. Approximately 3 minutes until the sixth dash appears. The six dashes will eventually disappear, one by one from the bottom. The show time of the dashed line spotlight continued for 30 minutes after it started.




May 21 at Senkoku-ishi


May 21 (Sun) First day of dashed line of light

Chunichi Shimbun reported the event.  Compared with yesterday, May 20th, we could clearly see four dashes of light today. We were interviewed by reporter Matsumoto from Chunichi Shimbun. It is the spotlight observation in Senkoku-ishi that takes place around 1 pm, thirty days before the summer solstice. The WEB NEWS is here Chubu Chunichi Shimbun (Hida) May 24, 2017. The visitors today were mainly from outside the prefecture. They began gathering at 12:30 pm.


And at night we lit the Big Dipper cup-marks. We were worried there might be clouds, but fortunately we could see the starry sky. Visitors from the prefecture arrived at 7:30 pm.


We could see the Big Dipper lying above us. Can you see it at the top of this photo? And low in the sky, Polaris sits above the megalithic group. This may be somewhat difficult to see but it is surely there in the photograph.

The Polar Star and the Big Dipper are far apart now, but about 5000 years ago they were closer. In other words, the North Star rotated around nearer the megaliths.

And when you connect seven of the nine cup-marks engraved on the megalith, the shape of the Big Dipper emerges. Isn’t it fantastic!

As you can see the picture above, the shapes of the actual Big Dipper and the stone cup-marks are mirror images. We do not know why this is so, but ancient people, in ruins around the world, also have inverted the shapes in the same way. And as to what the other two cup-marks mean … It seems that we contemporary people do not have any explanation.



Most of the universe is unknown. Modern people have only a small amount of information of the whole, and there is no way we can even deny the possibilities of ancient times. In this sense, the Kanayama megalithic group can be said to be an instrument that not only measures time but also can measure the thinking power of people.

In any case … the enjoyment of the starry sky finished around 9:30 pm. We are considering starry sky viewing once more this summer, with the solar observation society in July or August. Next time, the Big Dipper will not be seen as it will be hidden behind a tree, but we want to do a cup-mark lighting. We want to watch the Amanogawa Milky Way and the Summer Triangle (of the stars Altair, Deneb, and Vega). We hope to share our passion with many of you.