This calendar, and others like it, served an important imperial function in traditional China, for they were used to legitimize the prevailing power, in this case the Southern Ming. The calendars were probably brought to England by employees of the East India Company and collected by those who, like Ashmole, had an interest in astrology. It was given to Ashmole by the Oxford mathematician and astrologer Henry Coley, who produced annual astrological forecasts, or almanacs. 

Sinica 88, fol. 1r