The Gihō calendar (儀鳳暦, Gihō-reki), also known as Yi-feng li, was a Japanese lunisolar calendar (genka reki).
History
The calendar was created in China. It was first used in the Rintoku era during the Tang Dynasty.
The Gihō-reki system was brought from Korea to Japan in the Yi-feng era (676-678) of the reign of Emperor Gaozong of Tang. This calendar corrected errors in the Yuan-jia li (Genka calendar) which was developed in China. For a short time, both Genka and Gihō calendars were in use.
References
Gihō calendar Wikipedia(Text) CC BY-SA