Exploring Japan’s Unique Calendar System

Japan is a millennia-old region of Asia. This has led to unique customs and traditions passed down through generations. One of these long-held customs includes Japan’s unique calendar system. 

There have been a variety of official and unofficial calendar systems used in Japan. Currently, Japan utilizes the Gregorian calendar that began in 1873, with year labels reflecting the current Emperor’s reign year.

Japan is known for having animals associated with their calendar, but their systems are actually much more in-depth than that. They have changed over time, and they have taken inspiration from other cultures as well throughout the years. 

The Beginning Of The Japanese Calendar System 

The first calendar that Japan adopted was a lunisolar calendar. A lunisolar calendar is one that incorporates both the moon and the sun to determine the date. Japan first adopted the lunisolar calendar from Korea. Their calendar system changed over time to include Chinese customs, and then Japanese versions of Chinese customs. 

In the late1800s, the calendar system completely evolved. Japan adopted the solar Gregorian calendar. This is the calendar most often used in the majority of countries and is the one that Japan mainly uses today. 

The Gregorian Calendar 

The Gregorian calendar is credited to Pope Gregory XIII, as he developed it in the 1500s. He used inspiration from the Julian calendar, which revolved around a year being 365.25 days. The change introduced the leap year to the calendar, resulting in an extra day in February every four years. 

Other Systems For Designating Years In Japan 

Over the years, Japan has had other systems in place for designating years. These systems include: 

  • The Chinese Sexagenary Cycle: This was used in China to help record historical dates. One cycle revolves around sixty years. 
  • Era Name System: This was also used in China, and the years were named after emperors. 
  • Japanese Imperial Year: This calendar system was inspired by the date that Emperor Jimmu founded Japan 
  • Western Common Era: This system is commonly used academically and is similar to BC and AD. It is used to remove religious connotations. It is similar to the Gregorian calendar. 

Modern Lunar Calendar Elements Used In Japan Today

While Japan doesn’t use the lunar calendar anymore, they have continued some customs related to the calendar into today. For example, the twelve animals associated with the lunar calendar are still referenced in Japan.

Japan is well known for this, and many Western countries reference these animals when discussing years as well. 

These animals include: 

  • Horse
  • Sheep 
  • Monkey
  • Pig
  • Cow
  • Tiger
  • Mouse
  • Dragon
  • Snake
  • Rabbit
  • Dog
  • Rooster

Another aspect of the lunar calendar that is still witnessed in Japan is royuko. This represents the days of the week, which are divided into six days. Each of these days corresponds with good luck and fortune, as well as bad luck. 

Zodiac Scupture Portraying The Rat or Mouse

These six days, as well as what the day is expected to bring, are as follows: 

  • Senshou: This day brings good luck in the morning, but bad luck after noon. 
  • Tomobiki: This day allows for good luck during the entire day, except for at noon.
  • Senbu: The morning brings bad luck, but it changes to good luck after noon. 
  • Butsumetsu: The entire day is said to bring bad luck, as it is the day Buddha passed.
  • Taian: The entire day brings good luck and peace. 
  • Shakku: The whole day is bad luck, minus noon. 

The Years, According To The Japanese Calendar

The Japanese Calendar has used a few systems to determine years over time. The current system that is used is called nengo. This system revolves around Japanese-era names, which are named after emperors. 

Japan also used the koki system, or the imperial year system, for a short time until World War II. The first imperial year started when Emperor Jimmu founded Japan. The koki calendar determines leap years in a similar fashion to how they are determined on the Gregorian calendar. 

Imperial Palace Tokyo

The Months, According To The Japanese Calendar

Each month in the Japanese calendar has its own name, which are Japanese words for the first month, second month, all the way to the twelfth month. Japanese months also have their own traditional names. These traditional names represent what the month symbolizes. 

The names for each month are: 

  • January: Mutsuki, meaning Month of Love or Month of Affection
  • February: Kisaragi, meaning Changing Clothes
  • March: Yayoi, meaning New Life
  • April: Uzuki, meaning Unohana month, which is a flower
  • May: Satsuki, meaning Early Rice Planting Month
  • June: Minazuki, meaning Month of Water
  • July: Fumizuki, meaning Month of Erudition
  • August: Hazuki, meaning Month of Leaves or Month of Falling Leaves
  • September: Nagatsuki, meaning The Long Month 
  • October: Kannazuki, meaning Month of the Gods
  • November: Shimotsuki, meaning Month of Frost
  • December: Shiwasu, meaning Priests Running 

Japan also has its own names for the seasons. Spring is haru, summer is natsu, autumn is aki, and winter is fuyu

Hanami Season In Japan

The Days Of The Week, According To The Japanese Calendar

The Japanese names for the days of the week are very similar to the origins of the seven-day week. Each of the seven days was named after a planet in the solar system and originated in the Latin calendar system. 

Additionally, Japan also has its own terms for 10 day periods throughout the month. The first period is called jojun, the second period is called chujun, and the final period symbolizing the last few days of the month is called gejun

The days of the week in Japanese are called: 

  • Nichiyobi: This is Sunday, and the element associated with this day is the sun
  • Getsuyobi: This is Monday, and the element associated with this day is the moon
  • Kayobi: This is Tuesday, and the element associated with this day is fire, or Mars
  • Suiyobi: This is Wednesday, and the element associated with this day is water, or Mercury
  • Mokuyobi: This is Thursday, and the element associated with this day is wood, or Jupiter
  • Kinyobi: This is Friday, and the element associated with this day is metal, or Venus
  • Doyobi: This is Saturday, and the element associated with this day is earth, or Saturn

Tips For Reading A Current Day Japanese Calendar

Tokyo Skyline

At first glance, a Japanese calendar seems to be much different than a Western Calendar, despite both mostly following the Gregorian calendar system. This is because Japanese calendars still incorporate past calendar attributes, including era names still being used as years. For example, the current year in Japan is 3, and it is the year of the cow. 

The year will appear on the Japanese calendar as the number along with the current era name. Thus, the year 2021 on the Western calendar would read as Reiwa 3 on the Japanese calendar. This has been customary on a Japanese calendar since 1868

Knowing the era as well as the Japanese year is important for completing a lot of paperwork in Japan. Many pieces of stationary available in Japan, such as planners or agendas, will have a handy chart that outlines both the Gregorian and Japanese calendars for reference. 

Mount Fuji

Interesting Facts About The Reiwa Era

The Reiwa era is actually quite new, beginning in 2019. Before the Reiwa era, Japan was in the Heisei era. The emperor at the time, Emperor Akihito, actually stepped down from the throne because of health issues. This hadn’t been done in recent Japanese history, being that emperors are not supposed to leave the throne until they pass away. 

However, the law was changed to accommodate Emperor Akihito, who passed the throne to his son, Crown Prince Naruhito. That being said, the law change is not permanent, meaning that it will not apply to any future emperors who want to step down for the same reasons. 

Japan’s 85-year-old Emperor Akihito steps down from the throne, becoming the first Japanese monarch to abdicate in over 200 years

Important Japanese Festivals Throughout The Year

There are five seasonal Japanese festivals throughout the year that are known as the five sekku. These festivals are: 

  • Jinjitsu No Sekku: This festival is held on January 7th, and is a day of prayer for bountiful harvest. On this day, it is customary to indulge in nanakusa-gayu, which is a rice porridge with herbs. 
  • Momo No Sekku: This festival is on March 3rd, and is a festival that commemorates daughters. 
  • Tango No Sekku: This festival is celebrated on May 5th, and is a day to recognize children. It used to be called Boy’s Day in the past. 
  • Tanabata: This festival occurs on July 7th, and it’s also called the Star Festival. People will write ambitions on pieces of colored paper and post them in public places. 
  • Choyo No Sekku: This festival is on September 9th, and on this day, people will decorate temples with chrysanthemums to honor Imperial Japan, as it’s a flower associated with imperialism there.

Understanding Japanese Calendar And Eras

MT Lee
My fascination with Japan began several years back at a roadside bonsai stand while on vacation. I became more interested in the where and why's more than the trees themselves. My love of Bonsai led me to further research my interest in the gardens where they originated from and the places and people that surrounded those little trees. My curiosity was well rewarded upon visiting Saitama where the National Bonsai Museum was located and Omiya Village the bonsai mecca for lovers of this ancient art form. Exploring many towns and villages and even making my way to Japan's furthest southern prefecture of Okinawa. I hope to share my love of this wonderful and exotic place with all those who want to know more about Japan.