Map of Japan showing latitudes. The three main islands lies approximately 30 to 40 degrees north latitude. Image credit


In the Wosite language of Jōmon Japan, the winter solstice was termed, fuyu itaru hi, the day that winter (fuyu) arrives. In modern Japan, this same meaning is pronounced tōji. Yet in haiku over the years, the older indigenous fuyu itaru hi frequently appears.

As we have shown in other articles, the Jōmon certainly had used a solar calendar of their own making. The solar-tracking megaliths of Kanayama are evidence of this. This is natural in an early civilization so attuned to the life-giving sun.

Hiyomi and Koyomi

The solar calendar is confirmed in the Wosite writings of the same period, circa 5,000 years ago. They name a brilliant man named Achihiko Omoikane as its creator, for which he received the title, Hi-yomi-no-miya, Master of the Solar Calendar. Until that time, calendars were called koyomi (ko-yomi), meaning to read the trees for the seasons. Even though Japan now uses the Gregorian solar calendar, the word for calendar is still koyomi!

Achihiko showed how to read the sun for more accurately knowing the seasons of the year. For practical reasons in a rural landscape without electricity or flashlight batteries, indigenous people relied on lunar phases to mark the days. However, the lunar calendar does not match well with the solar year; too many adjustments are needed. The people of Wosite times wanted to know the solar year which tells the seasons for practical purposes such as fishing, hunting, and agriculture. 

One might speculate that the earliest shrines in the form of standing megaliths or grove of sacred trees were oriented toward the east, and we have seen many cases of this. Later, perhaps, their astronomical knowledge enabled them to place shrines solsticially. 

Winter Solstice Sunrise

In the land of Japan, between 30 to 40 degrees north latitude, the winter solstice sun rises and sets 30 degrees south of the east-west line. In field trips to hundreds of old shrines, we have found a predominance of shrines facing either the sunrise or the sunset of winter solstice. This implies that ancient people knew how to determine these solstice directions. And they found it significant to orient their sacred places to honor the sun’s return to the north. 

One of the oldest shrines in Japan is the Asadori Jinja. Its origin is unknown. Yet, the local Shinto priest conducts a ceremony starting just before dawn on winter solstice morning. The villagers have assembled to greet the sun as it rises. At first light, they shout “ka-kee kō!” Thus the name of the shrine, Asa-dori, which means the Bird of Morning, the rooster. 

Solar Observations of the Kanayama Megaliths

On the Higashinoyama (Eastern Mountain) of Kanayama are a grouping of lying megaliths some 9 meters long. They point to the sun as it clears the terrain on the morning of the winter solstice. 

Moreover, observations can be made 60 days before and after this date. (Solar observations can be made more accurately when the sun is not near solstice). The earlier date gives advance notice of the day that winter solstice will arrive so that they could prepare their ceremony. As well, this is an important date in their solar calendar as we shall shortly explain.

By careful observations over long periods of time, the Jōmon people knew the four-year leap-year cycle as well as the longer 128-year cycle. Theirs is an observational calendar, always true to the actual movement of the sun.

In the Wosite literature the winter solstice marked the beginning of the new year. Our own Gregorian calendar begins the new year on January 1, ten days after the winter solstice. Was this choice deliberate? The Solar calendar of the Jōmon was deliberately designed “from scratch,” so to speak.

Kanayama Solar Calendar with Six Seasons 

The Kanayama solar calendar is noteworthy for its six-part symmetry. Each season is approximately 60 days long. In this chart, we have placed winter solstice at the bottom, when the sun is lowest in the sky, furthest south. The calendar reads clockwise. Let’s approximate the year as having 360 days. Then the 60 days before winter solstice may be considered to begin the early winter season, and 60 days after winter solstice marks the end of late winter and the beginning of the 60-day spring season. Spring lasts, on this calendar, from 30 days before to 30 days after the vernal equinox. And so it goes for the rest of the year until the calendar and the sun cycle back around. In this chart from the Kanayama Research Center, the dates shown in red are actual dates when multiple solar observations are made at the megaliths.

On wall calendars in the U.S., the winter solstice date is labelled the “first day of winter.” In the U.K., this day is termed “midwinter day.” It’s interesting that the U.K. custom matches the six-season calendar.

Asanoha Sacred Symbol

The six-fold symmetry of the solar calendar is reminiscent of the sacred symbol of the asanoha motif. Asanoha represents the vigor of the asa hemp plant, sacred to the people. The asanoha pattern is often found in children’s clothing and dishes to wish good health and longevity. The asanoha pattern shown here on the left in woodwork is the Japanese version of the flower of life. The diagram on the right is a copy of the flower of life pattern in stone of the Temple of Abydos in Egypt. 

Hemp is known for being long used in making ropes for its strength and durability. While growing hemp was banned for a period of time in certain countries when it was thought to contain THC, the hallucinatory chemical in marijuana, the hemp plant is now making a comeback to legality and is serving for health and medicinal purposes, as it was meant to do. It is also a sustainable plant and is being more widely used in ecofriendly fabrics.

Astronomical Cross Quarters of Space

We find that the four dates which delineate the boundaries of the 120-day summer and winter seasons are known to astronomers as the cross-quarter dates. These dates do not divide the temporal year into four parts of 91 days each. Rather, they divide the times of the year when the sun’s path in the sky moves into another of the four zones. With the solstices marking the extreme borders, there are six calendar dates dividing the Jōmon calendar into six seasons. This is very interesting, since the ancient Vedic calendar of India has the same six seasons. However, the Vedic calendar is based on stellar observations and will gradually cease to match the solar year as the star patterns in the sky change due to a precessional cycle of around 26,000 years.

In this NASA chart , the zone occupied by the sun in the sky is bordered by the red arc for summer solstice and the green arc for winter solstice. It is divided into two parts by the path of the sun during the equinoxes, shown in blue. The cross-quarters are the further division of each half again into half, thus forming four quarters of the sun’s zone. By this, we mean the angles are divided into half. For example, for latitudes around 35 degrees the red and green arcs are separated by 60 degrees; the half-way angles are separated by 15 degrees. 


In conclusion, we have discussed the Jōmon indigenous solar calendar. We have pointed out some aspects of ancient calendars and how the sun is observed on certain days of the year, including the winter solstice. The winter solstice has served as the start of the new year in many indigenous cultures as well as in Japan. 

The return of the sun on the winter solstice is certainly a cause for celebration!

P.S. A related winter solstice post on Iwakage, the blog site of the Kanayama Megaliths is here.