What Were the Old Names for the Months in Japanese?

Japanese calendar with a full-color scene an a verse written in English.
George C. Baxley/Wikimedia Commons/Public Domain

In modern Japanese, the months are simply numbered from one to 12. For example, January is the first month of the year, therefore it is called "ichi-gatsu." 

The Old Japanese Calendar Names

There are also old names for each month. These names date back to the Heian period (794-1185) and are based on the lunar calendar. In modern Japan, they are not normally used when saying the date. They are written in a Japanese calendar, sometimes, along with the modern names. The old names are also used in poems or novels. Of the 12 months, yayoi (March), satsuki (May), and shiwasu (December) are still referred to quite often. A fine day in May is called "satsuki-bare." Yayoi and satsuki can be used as female names.

Modern Name Old Name
January ichi-gatsu
一月
mutsuki
睦月
February ni-gatsu
二月
kisaragi
如月
san-gatsu san-gatsu
三月
yayoi
弥生
April shi-gatsu
四月
uzuki
卯月
May go-gatsu
五月
satsuki
皐月
June roku-gatsu
六月
minazuki
水無月
July shichi-gatsu
七月
fumizuki
文月
August hachi-gatsu
八月
hazuki
葉月
September ku-gatsu
九月
nagatsuki
長月
October juu-gatsu
十月
kannazuki
神無月
November juuichi-gatsu
十一月
shimotsuki
霜月
December juuni-gatsu
十二月

shiwasu
師走

Name Meanings

Each old name has meaning. 

If you know about the Japanese climate, you might wonder why minazuki (June) is the month of no water. June is rainy season (tsuyu) in Japan. However, the old Japanese calendar was about a month behind the European calendar. This means minazuki was from July 7th to August 7th in the past.

It is believed that all the Gods from throughout the country gathered at Izumo Taisha (Izumo Shrine) in kannazuki (October), and therefore, there were no gods for other prefectures.

December is the busy month. Everyone, even the most respected priests, prepares for the New Year

Old Name Meaning
mutsuki
睦月
Month of harmony
kisaragi
如月
Month of wearing extra layers of clothes
yayoi
弥生
Month of growth
uzuki
卯月
Month of Deutzia (unohana)
satsuki
皐月
Month of planting rice sprouts
minazuki
水無月
Month of no water
fumizuki
文月
Month of literary
hazuki
葉月
Month of leaves
nagatsuki
長月
Autumn long month
kannazuki
神無月
Month of no Gods
shimotsuki
霜月
Month of frost
shiwasu
師走
Month of running priests