Creating the Japanese Calendar: Time, Myth & History
In the West, a calendar is often viewed merely as a tool for scheduling meetings and tracking holidays. However, in Japan, the creation of the calendar—known as Koyomi—is a profound cultural practice deeply rooted in nature, astronomy, and imperial authority. The history of “creating the calendar” in Japan is a fascinating journey from ancient Chinese divination to the high-tech precision of modern Tokyo, bridging the gap between the spiritual and the practical.
The Origins of Timekeeping in Japan
The concept of a structured calendar was not indigenous to the Japanese archipelago; it was imported. In the mid-6th century, the sophisticated lunisolar calendar system arrived from China via the Korean peninsula. Before this, ancient Japan relied on natural cycles—the blooming of cherry blossoms, the migration of birds, and the phases of the moon—to dictate agricultural activities.
The formalization of the calendar became a crucial duty of the Imperial Court. By the Nara and Heian periods, the government established the Onmyoryo (Bureau of Onmyo), an office dedicated to astronomy, divination, and calendar-making. These early calendars were not just about dates; they were almanacs predicting solar eclipses, prescribing lucky directions, and determining auspicious days for state ceremonies. The ability to control and predict the calendar was synonymous with political legitimacy, as the Emperor was seen as the mediator between the heavens and the earth.
Legend: The Moon God and the Separation of Day and Night
While historical records point to Chinese imports, Japanese mythology offers a divine explanation for the passage of time and the distinction between day and night, which forms the basis of any calendar.
According to ancient texts, the Shinto pantheon includes Tsukuyomi-no-Mikoto, the Moon God. Born from the right eye of the creator god Izanagi, Tsukuyomi was entrusted with ruling the night, while his sister, the Sun Goddess Amaterasu, ruled the day. A famous legend recounts a banquet where the goddess of food, Uke Mochi, created a feast by vomiting it up. Disgusted by her actions, Tsukuyomi killed her.
Amaterasu, horrified by her brother’s violence, vowed never to see him again, moving to the opposite side of the sky. This mythological separation explains the alternation of day and night. This duality is central to the traditional Japanese lunisolar calendar, which harmonizes the cycles of the moon (Tsukuyomi) with the solar year (Amaterasu) through the use of intercalary months—a “leap month” inserted to keep the seasons in sync.
Modern Culture: The Legacy of the Lunisolar Calendar
Japan officially adopted the Gregorian calendar on January 1, 1873, during the Meiji Restoration, in a bid to modernize and align with Western powers. However, the soul of the Koyomi remains vibrant in modern Japanese culture.
The Rokuyo System
You will often see small kanji written next to dates on contemporary Japanese calendars. This is the Rokuyo (Six Days), a cycle derived from the old lunisolar calendar that predicts the luck of the day.
- Taian: The luckiest day, perfect for weddings.
- Butsumetsu: The unluckiest day, traditionally avoided for celebrations but acceptable for funerals.
- Tomobiki: A day where luck impacts friends; often avoided for funerals to prevent “pulling friends” into death.
The 24 Sekki and 72 Ko
Modern Japan also celebrates the 24 Sekki (solar terms) and the 72 Ko (micro-seasons). While the Gregorian calendar tells you it is April 5th, the traditional calendar poetically describes the time as “The Swallows Return.” This deep appreciation for ephemeral seasonal shifts influences everything from Haiku poetry to the seasonal ingredients used in Kaiseki cuisine.
Traveler’s Tips: Experiencing the Calendar
For travelers visiting Japan, the concept of the calendar offers unique cultural touchpoints:
- Buy a Jingu-reki: If you visit Ise Jingu (Ise Grand Shrine), you can purchase a traditional almanac known as Jingu-reki. It is considered the most authoritative version of the traditional calendar and makes for a unique, spiritual souvenir.
- Check the Rokuyo: If you plan to visit famous shrines or temples, checking the Rokuyo can help you predict crowds. Taian days are often crowded with wedding processions, offering a glimpse into traditional ceremonies, while Butsumetsu days might be quieter.
- Seasonal Illuminations: Understanding the Sekki helps you catch specific events. The transition points, such as the Spring Equinox (Shunbun) or the Winter Solstice (Toji), are often marked by specific temple festivals, special foods (like pumpkin on Toji), and yuzu baths at onsens.
Sources & Further Reading
To delve deeper into the mythology and history of Japanese timekeeping, the following texts are essential:
- The Kojiki (Records of Ancient Matters): For the myths regarding Izanagi, Amaterasu, and the divine lineage.
- The Nihon Shoki (The Chronicles of Japan): Provides the historical account of the introduction of the calendar system from the continent and the legend of Tsukuyomi.
- The Tale of Genji: Offers insight into how the aristocracy of the Heian period relied on Onmyodo and the calendar for daily decisions and courtly rituals.