Dutch works on physical and medical sciences. Dutch learning became popular and
served as the basis of culture in the late Tokugawa period.
1.2 Calendar Reforms
The first calendar used in Japan was imported from China in 554 A.D. during the
regime of Emperor Kinmei (欽明), and several successive emperors also adopted
new Chinese calendars without any revisions. Finally, it was in 862 that the HsuanMing calendar (Senmyo reki, 宣明暦) was imported from China and promulgated for
yearly use.
This calendar was used for more than 800 years, despite the growing discrepancies between observed phenomena and the calendar.
In the sixteenth century, the situation surrounding Japan changed dramatically. In
1543, a Portuguese ship came shore and introduced Western civilization to Japan for
the first time. In 1549, Francis Xavier, a Jesuit priest, also landed on the southwest
shore, and Christian evangelism was received with enthusiasm in some Japanese
quarters. In 1603, the Tokugawa government was established in Edo and lasted for
around 250 years, accompanied by domestic peace and economic prosperity. These
two factors, the impact of the West and national stability, made possible the calendar
reform during the Tokugawa period. In Western countries, the Julian calendar was
replaced by the Gregorian calendar in Catholic countries in 1582, but it took around
200 years for it to be accepted in Protestant countries. Since these calendars were of
the solar type, the reform had no direct impact on lunisolar calendars in China and
Japan. Impacts may have been confined to technical areas, such as mathematical and
observational techniques.
The official astronomical office in the Tokugawa era was the Tenmonkata (天文
方, Bureau of Astronomy and its personal position) in Edo and the On-yo Ryo
(Yin-Yang Board, 陰陽寮, Office of Astrology) in the Kyoto Imperial Court.
1.2.1 Shibukawa Harumi and Jokyo Calendar
Shibukawa Harumi (渋川春海, 1639–1715) inaugurated Japan’s first calendar
reforms after many centuries based on Western astronomical ideas and techniques.
Harumi was born into the Yasui family, a professional GO (碁, board game)
player. From his youth, Harumi had the reputation of being a prodigy in GO play and
showed a remarkable understanding of astronomy, particularly calendar reform.
With his calendar works, Harumi was recommended to the Shogun by Clan Lords
as the most qualified person to carry out calendar reform.
It was the Chinese Shou-shih calendar (Juji reki, 授時暦) that Shibukawa had
taken as the basis of his calendar reform. This calendar was produced in 1281 by
2
1 Astronomy in the Tokugawa Period, 1603–1868
served as the basis of culture in the late Tokugawa period.
1.2 Calendar Reforms
The first calendar used in Japan was imported from China in 554 A.D. during the
regime of Emperor Kinmei (欽明), and several successive emperors also adopted
new Chinese calendars without any revisions. Finally, it was in 862 that the HsuanMing calendar (Senmyo reki, 宣明暦) was imported from China and promulgated for
yearly use.
This calendar was used for more than 800 years, despite the growing discrepancies between observed phenomena and the calendar.
In the sixteenth century, the situation surrounding Japan changed dramatically. In
1543, a Portuguese ship came shore and introduced Western civilization to Japan for
the first time. In 1549, Francis Xavier, a Jesuit priest, also landed on the southwest
shore, and Christian evangelism was received with enthusiasm in some Japanese
quarters. In 1603, the Tokugawa government was established in Edo and lasted for
around 250 years, accompanied by domestic peace and economic prosperity. These
two factors, the impact of the West and national stability, made possible the calendar
reform during the Tokugawa period. In Western countries, the Julian calendar was
replaced by the Gregorian calendar in Catholic countries in 1582, but it took around
200 years for it to be accepted in Protestant countries. Since these calendars were of
the solar type, the reform had no direct impact on lunisolar calendars in China and
Japan. Impacts may have been confined to technical areas, such as mathematical and
observational techniques.
The official astronomical office in the Tokugawa era was the Tenmonkata (天文
方, Bureau of Astronomy and its personal position) in Edo and the On-yo Ryo
(Yin-Yang Board, 陰陽寮, Office of Astrology) in the Kyoto Imperial Court.
1.2.1 Shibukawa Harumi and Jokyo Calendar
Shibukawa Harumi (渋川春海, 1639–1715) inaugurated Japan’s first calendar
reforms after many centuries based on Western astronomical ideas and techniques.
Harumi was born into the Yasui family, a professional GO (碁, board game)
player. From his youth, Harumi had the reputation of being a prodigy in GO play and
showed a remarkable understanding of astronomy, particularly calendar reform.
With his calendar works, Harumi was recommended to the Shogun by Clan Lords
as the most qualified person to carry out calendar reform.
It was the Chinese Shou-shih calendar (Juji reki, 授時暦) that Shibukawa had
taken as the basis of his calendar reform. This calendar was produced in 1281 by
2
1 Astronomy in the Tokugawa Period, 1603–1868