2022 Autumn Equinox at the Iwaya-Iwakage Grouping

The first spot of light appeared around 09:03 am. This photo was taken at 09:05 am.

A typhoon and heavy rains accompanied autumn equinox in Japan this year, on September 23. Fortunately, the 24th was a sunny day and observations could be made in the Iwaya-Iwakage grouping. These photos were kindly shared by Ms Chika. All photos are dated 2022-09-24. We give only the hour and minute in the captions.

By time 09:10, the spotlight had taken on the anticipated oval shape.
Time 09:11, the oval is near a line on the surface of the slab.
Three minutes later, the oval has moved to the other side of the line.

The camera is facing north, the sun is moving from due east to west in the sky. Thus, the spotlight on the floor of the Iwaya-Iwakage chamber moves from west to east, or left to right of the viewer.

We thank Ms. Chika for once again sharing her photos of seasonal observations with us.


2022 Summer Solstice at the Senkoku Grouping

Summer solstice sun rises through this gap; Stone C is on the right (p30).

Summer solstice 2022 has arrived at the Kanayama Megaliths. Ms. Chika has sent us these photo taken on two days that were intermittently rainy, cloudy, and sunny. The page numbers refer to the Kanayama Megaliths Guidebook. The first photo above was taken on June 21 at 6:47 when the sun has risen but is obscured by the cloudy sky. The next photo (below) shows an observer standing in front of Stone A on June 21 at 6:46 am. It is too early to see the sun over Stone C. See the last photo.

This man is standing in front of Stone A as he awaits the sun rising over Stone C. The lower grotto is immediately to his left, while the upper grotto can be entered through the opening between Stone A and its adjacent Stone A’.

Below are three photos taken from inside the upper grotto later in the morning.

This is where the sunlight enters the upper grotto, photo taken at 16:00 (p34).

The photo below is the sight that the observer above was waiting to see; he would have had to wait until at 8:22 a.m.

Summer solstice sun appears at the top center of Stone C at 8:22 on 2022.06.21 (p31).

The above is Stone C as observed from Stone A. The morning sun will clear the corner at the right on the autumn equinox. It will again be seen next spring equinox at the same spot.

P.S. Since the sun is almost at a standstill on the solstice (which means sun standing still), the events of June 20, 21, and 22 are nearly identical. And due to the cloudy and rainy weather pattern in the mountains of Kanayama, observers must plan to go a day ahead and a day after the precise astronomical date. Still another consideration is which year it is in the four-year (and higher) cycle of leap years which regularly cause a drift in the dates of the events.

Let us enjoy the cycles of the sun at the Kanayama Megaliths!


June 21 2022 – the solstice

Elevation of the sun, in degrees, at 50 degrees north latitude. From Explaining Science

Explaining Science has posted an article entitled, June 21 2022 – the solstice, of interest to the readers of Iwakage. The above illustration from that post shows that the sun reaches its greatest elevation on the 21st of June in the U.K. It is also the date of the maximum hours of daylight. The article goes on to state:

The precise astronomical definition of the June solstice (also called the summer solstice in the northern hemisphere) is the exact point in time when the North Pole is tilted furthest towards the Sun. 


UTC Time Zone Map

UTC time zone map, by https://www.timeanddate.com/time/map/#!cities=136

We call your attention to a handy site for looking up the time anywhere in the world. Go to


You will find a map like that shown above, but on the site the map will have active red points. Click on one of them for more info about that location. For example, clicking on the red dot in Japan gives you the following information:

Lat/Long:35°41’N / 139°42’E
Elevation:44 m
Currency:Yen (JPY)
Country Code:+81
Country information for Japan, https://www.timeanddate.com/worldclock/japan/tokyo

In addition, you will see a clock with the exact date and time, as well as the current weather in Tokyo. Other information includes sunrise and sunset times, moon phase, even high and low tides, and country holidays.


Dashed Spotlight of May 2022

Dashed spotlight 2022.05.22 12:58am JST. Photo by Chika.

Just in from Kanayama Megaliths

The dashed spotlight of the Senkoku-ishi megalithic group has returned in 2022. This photo was taken hours ago by Ms Chika. The arrival of the dashes signifies that the summer solstice will occur in around 30 days.

Update of May 24. This photo was taken by Kazuo Sugisaka on May 24 JST. Notice that, two days later, the dashes are wider and a sixth dash of light has appeared at the bottom of the triangular slab. Thank you to Chika-san and Sugisaka-san for sharing their photos with us.

Six dashes, photographed by Kazuo Sugisaka on May 24, 2022.


Calendar: 5. UTC Global Solar Calendar

The UTC Global Solar Calendar. By Shiho Tokuda.

UTC Global Solar Calendar

We present above the first appearance of the UTC Global Solar Calendar. The Global Calendar is determined by the four astronomical quarter dates (the equinoxes and solstices) and the four astronomical cross-quarter dates (ACQ dates). The ACQ dates are also called “midway” dates; see our earlier posts in this series.

The eight astronomical dates and times are given in the table below, and were obtained from the website of the National Astronomical Observatory of Japan. Solar longitude is measured in degrees from the vernal equinox. “Midway” indicates the sun’s altitude as being midway between the adjacent equinox-solstice altitudes. These four midway dates appear on the diagonals of the circular calendar. Notice that the equinoxes do not determine the boundaries of any season. That is why there are six seasons in this calendar, and only six of the eight dates are necessary to define the seasons. The dates are UTC dates.

Eight astronomical UTC dates for 2022

To our knowledge, this Global Solar Calendar has only been fully documented by our Kanayama Megaliths Research team of Japanese, German, and American investigators. We have previously presented the Global Solar Calendar with dates appropriate for Japan Standard Time. Please recognize that dates shift slightly over the years. This can be seen in the table below, showing the UTC dates of the December solstice. Notice that, while it usually occurs on 12/21, it falls on 12/22 in the year before a leap-day. There is a leap year every four years to keep the calendar in synch with the seasons. In Kanayama, the megaliths also tracked dates correct to the next longer cycle of 128 years, making it more accurate than the Gregorian calendar which makes the next correction every 100 years.

Winter solstice dates 2017-2027. From Calendarpedia.com

Japan Standard Time JST = UTC + 9 hours, which often makes their astronomical dates a day ahead of say, Hawaii. Make the conversion for your time zone. For example, Hawaii’s HST = UTC – 10 hours. We see immediately that the time difference between JST and HST is 19 hours, nearly a whole day.

Six Seasons

Ms. Shiho Tokuda remarked that the dates of the sun’s midway paths mark the beginnings of significant seasonal changes in Japan. As we can see, the Japanese people are keenly aware of nature’s cycle. We summarize the changes observed in nature at the start of the seasons.

Dec. 21 Tõji, winter solstice, starting of late winter season

Feb. 18 Yukidoke, thawing snow, starting of spring season. In the thawing season, sansai wild mountain plants (such as the fukinotō butterbur) begin to appear from under the snow.

Fukinoto, butterbur. Credit.

April 20 Kaika, flowering, starting of early summer season. The season for coming into bloom begins with cherry blossoms, mountain azaleas, and erythronium flowers.

June 20 Geshi, summer solstice, starting of late summer season

Aug. 23 Akikaze, autumn breezes, starting of fall season. In the evening, the autumn breeze begins to blow and you begin to hear the sound of insects.

Oct. 23 Kōyō, autumn colors, starting of early winter. The deep green of the mountains begins to turn red, and the season of fall foliage has begun.

Autumn colors at Kanayama Megaliths, by Shiho Tokuda

“I think that the seasons of Japan change their facial expressions as if they symbolize the richness of the forest, and have an impact on people’s spirits.” Shiho Tokuda


2022 Spring at the Kanayama Megaliths

2022 April 7 Sakura in bloom at the megaliths. The building to the right is the simulator. The megalith beyond it is the North Star-viewing stone. Photo by Shiho Tokuda.

Sakura Blossoms

Spring has arrived at the Kanayama Megaliths! The sakura were in full bloom on April 7, and have dropped by this time. The report is here in Japanese, with additional photos.

Kazuo Sugisaka Appointed

Spring also brought the announcement that our friend who has contributed many photos and reports, Mr. Kazuo Sugisaka, has been appointed maintenance manager of the Megaliths. Congratulations, Sugisaka-san! The photo below shows him atop one of the megaliths, pruning the ケヤキ zelkova tree.

Kazuo Sugisaka is at upper left in this photo by Shiho Tokuda.


Calendar: 4. Global Solar Calendar

Kanayama Megaliths Solar Calendar, a global solar calendar. Art by Shiho Tokuda.

Kanayama Megaliths Solar Calendar

The solar calendar of the Kanayama Megaliths is depicted here. We will also call it the Six-Seasons Global Calendar. Winter solstice 12/22 is at the bottom. In the three previous posts, we have explained how this calendar is constructed from the four yearly quarter dates (the solstice and equinox dates), plus the four astronomical cross-quarter ACQ dates. In the numerous reports we have posted on this Iwakage site about observational events throughout the years, you have seen how field data are collected to establish where we are in this yearly cycle.

The Calendar is a framework for the cycle of seasons of the year. It is kept accurate by real-time observations of solar events. Some of the observational events are spots of light on surfaces which are made by beams of light from the sun. They are observed only on certain dates of the year. Another type of observation is sighting the sun along certain directions at certain times. There are other methods as well.

The red dates shown on the Calendar are dates of actual observations. There are eight specific dates. The eight dates are the usual four: two equinoxes and two solstices, plus four ACQ dates. Please note how important these ACQ dates are. They divide the circle in such a way as to delineate six seasons rather than the usual four.

Six Seasons of the Year

In the Calendar, there are six seasons of the year. Starting at the time of the winter solstice, the seasons are as follows.

60 days of Late Winter

60 days of Spring

60 days of Early Summer

60 days of Late Summer

60 days of Autumn

60 days of Early Winter

Six-Season Global Calendar

Why is this six-season calendar a global calendar? Because it holds around the world, independent of latitude of the observer. You have seen how the calendar was derived. The observational dates required to determine the calendar are valid independent of latitude. The four astronomical events of solstices and equinoxes are known by their UTC times and do not depend on your location. Neither do the four astronomical cross-quarter dates, the ACQ dates, depend on your location. However, to know what clock-time the event occurs, you must convert UTC to the local standard time which is on your clock. 

Six-fold Sacred Geometry

The six-fold geometry is considered sacred geometry. It is found in nature in the hexagonal shapes of honeycombs of bees. All snowflakes have a six-fold geometry, and it is said that each snowflake is unique. The asanoha pattern is very special in Japan. Asanoha is the leaf of the hemp (asa) plant and it represents vitality, especially for infants and children.

Traditional Japanese asanoha pattern in kumiko woodcrafting.

There are many six-fold Islamic patterns. The flower of life is a sacred pattern found on Egyptian monuments.

Sacred Calendar

The Six-Season Calendar has been used by Hopi in North American and by ancient Vedic India. The cross-quarters may have been deliberately observed in Egyptian monuments.

The Six-Season Calendar of the Kanayama Megaliths depends only on the astronomical relationship of earth and sun. It is totally natural and may be considered a sacred calendar.

Kanayama Calendar, Global Calendar, Sacred Calendar

We have come to know and appreciate the beautiful and profound six-season calendar. We may feel intrinsically that the Kanayama Calendar is a global calendar and a sacred calendar.


Calendar: 3 Sinusoidal Sun, Lahaina Noon, and Six Seasons

Solar Declination is Sinusoidal

To understand the calendar theoretically, we need to study the sun’s declination and its altitude over the course of a year. Solar declination is the angle between the sun’s rays and the plane of the earth’s equator. It is shown above as 23.4 degrees for summer solstice when the sun appears highest in the sky.

Solar year: earth orbits sun (https://explainingscience.org/)

By agreeing on this definition of declination, and since the earth’s orbit around the sun is nearly circular, the combined effect of viewing the sun from earth over a linear time period of a year we obtain the sinusoidal graph below. Sinusoidal is an adjective meaning like a sine function, a sine curve, shown here.

Sinusoidal function. Credit here.

When we calculate the declination of a theoretical earth-sun system from geometrical principles of earth in orbit, we get a sine curve for angle versus time. The y-axis corresponds to the declination angle. The time from peak to peak (or minimum to minimum) is a solar year. The peaks correspond to summer solstices in the northern hemisphere, the valleys to winter solstices. We readily see why the solstice means “sun standing still.” The sun stays at nearly the same declination for quite a few days. This is similar to the moon appearing to be full for a few nights. The reason is a slowly changing geometry. In contrast, during the equinoxes, the sun-earth relationship is rapidly changing as the angle goes through zero.

Declination and Altitude

Notice that declination is relative to earth’s equator, rather than altitude which is relative to earth’s north pole. Therefore, the altitude of the sun seen by an observer at a certain north latitude is the altitude angle (in degrees),

         Altitude = 90 degrees – (north latitude – solar declination) 

  = 90 degrees – north latitude + solar declination


         Altitude = solar declination + (90 degrees – north latitude)

Lahaina Noon

For the special case in which the observer is at the Tropic of Cancer at 23.4 degrees North and the date is the summer solstice when the sun’s declination is 23.4 degrees, then the altitude observed at local noon is 90 degrees, the zenith which is straight up. In tropical places such as Hawaii, the sun passes through the zenith on two days of the year. Those two days are popularly called Lahaina Noon, and depends on the latitude in Hawaii. The Bishop Museum in Honolulu publishes Lahaina Noon dates each year. https://www.bishopmuseum.org/lahaina-noon/.  For the year 2022, some dates are given here. 

South Point, Hawaii Island, 18.9N: May 14 12:19 pm, July 27 12:29 pm

Honolulu, Oahu Island, 21.3N: May 26 12:29 pm, July 16 12:30 pm

Lihue, Kauai Island, 22N: May 30 12:35 pm, July 11 12:43 pm

Note that, the closer to the latitude of the Tropic of Cancer, the closer the two zenith dates are to the summer solstice which is June 21 0914 UTC in 2022.

Okunomichi has published a number of posts about Lahaina Noon. There is also a post on this Iwakage site. Please use the SEARCH box to find the posts.

Why the Midway Dates are Spaced 60 and 30 days 

When we examine the shape of the sine curve, we observe several things. In one cycle (called a period) there is a maximum and a minimum. There are two crossing points in time where the sine is zero. From the graph we see that: minimum, zero crossing, maximum, zero crossing, minimum, are equally spaced in time.

Next, ask yourself: when do the midway points occur in time? Midway points are when the angle (the sine) is halfway between zero and the maximum or minimum, or between the halfway point and maximum or minimum. Are these points midway in time? The answer is:  NO. 

Either from the curve or from mathematics, we find that the time from zero to the midway point (half of the maximum) is half as long as from the midway point to the maximum. (The reason is the slowing down of the declination near the maximum.) When we scale the time axis to one calendar year of approximately 360 days, those intervals are 30 days and 60 days.

Note: Although we said we model (approximate) the year as having 360 days, the ancient solar year may at one time have been 360 days. There are ancient records that attest to this, as well as some modern theories.  

Six Seasons are based on Astronomical Cross-Quarter Dates

Now we understand that, due to the geometry of earth’s circular orbit and measuring time linearly for a yearly calendar, the astronomical events are spaced in this interesting pattern:

Winter solstice to spring ACQ = 60 days

Spring ACQ to spring equinox = 30 days

Spring equinox to summer ACQ = 30 days

Summer ACQ to summer solstice = 60 days


Please keep these facts in mind as we go on in the next post to develop the Kanayama Solar Calendar which has six seasons.

Kanayama Solar Calendar


2022 Spring Equinox

Setting sun on March 20, 2022 at 16:57. All photos by Ms Chika.

Spring Equinox Setting Sun

Spring equinox occurred in Japan on March 21, 2022. Ms Chika was in Kanayama the day before to capture the sun setting in the west between the boulders of Iwaya-Iwakage, as shown above.

Spotlight in Iwaya-Iwakage

The spotlight in Iwaya-Iwakage takes on a variety of shapes during the days of the year. It is fascinating to watch the changes even in a single day. On the spring equinox, between 9:35 to 9:41, the following photos were taken. Note how the oval shape of the spotlight matches the oval template stone made by the Jomon people of long ago. Then, the spotlight “slides” off the platform stone as it moves to the right (because the sun is moving to the left which is west).

Then the spotlight takes on a triangular shape, with its base parallel to its line of movement. This photo above, taken at 10:59, shows how the spotlight fits perfectly in the marking of previous years.