Zhang Yong’s contribution to study of Vietnamese ancient calendars.

Abstract

Zhang Yong’s Contribution to the Study of Vietnamese Ancient Calendars
Zhang Yong is a Chinese who was born in England (1911) and studied in Germany (1929-1936). He went to Hanoi (1938) and read the books in École française d’Extrême-Orient. He reads the ancient Vietnamese calendar Bách trúng kinh A2517 (which is now lost) and shortly after wrote an article Study on the first days of month and bissextile months of Vietnamese Calendar. In 1939 Zhang Yong went to Hong Kong (a ceded land to England) for illness treatment, then died there. He also promptly submitted the above article to the Journal Study Southwest to publish in the first issue of 1940.
With the above article, Zhang Yong - a foreigner - became the first person to study the ancient Vietnamese calendar and made some important contributions. The above article has preserved the essence of the book Bách trúng kinh A2517. The article shows that the edited Lịch đại niên kỷ bách trúng kinh (1740-1883) A1237 is completely similar to the Bách trúng kinh A2517 (1758-1886), and our editing method is reliable. The article of Zhang Yong helped us find the Tây Sơn calendar of the year of Gui Chou (1793), which was previously not confirmed. It is important that thanks to Zhang Yong’s article, we have a second version of the Tây Sơn Dynasty calendar (from 1789 to 1801) as well as a second version of the official Nguyễn Dynasty calendar from 1851-1886 via Bách trúng kinh A2517 to increase the reliability of research conclusions.