Why is the perpetual calendar produced by each manufacturer different?

The perpetual calendar produced by each manufacturer is different, which is the result of the different basis, methods and bibliography used in choosing auspicious days.

Gregorian calendar is the best carrier for choosing auspicious days. In order to facilitate people to choose auspicious days, the content of choosing auspicious days in the past was compiled by the state, so the conclusion of choosing auspicious days is the same.

After the founding of People's Republic of China (PRC), China's calendar was compiled by the state, but the state did not compile some auspicious contents. Before the reform and opening up, the calendar did not list auspicious content; After the reform and opening up, various publishing houses have included the contents of Auspicious Selected Journals in their calendars. Because each publishing house organizes its own personnel to compile the contents of Auspicious Selection, the differences in basis, methods and bibliography will inevitably lead to different conclusions about Auspicious Selection.

With the development of science and technology, in order to facilitate the people, the perpetual calendar has now been made into an electronic version, that is, an electronic perpetual calendar. People can also use Baidu search to search for "perpetual calendar" at any time.