I want to buy a perpetual calendar with eight characters at each time under the date.

It's just that the calendar interface is hard to find. The calendar written by Qin Yi-ology master is very good. Please find it! There are books on the "Book of Changes" or "Philosophy" shelves in bookstores. There is also a mysterious auspicious calendar on the internet, which is very good, not only with eight characters, but also with dream interpretation and Peng Zuji. Not much, just about 5 meters.