Basically correct. There is basically no objection to Chinese characters, and how to read and write them, mainly Arabic numerals, depends on the specific situation. For example, "AD 1999" can be read as "AD 1999" or "ad1999"; However, "65438+February 2 1" is generally pronounced as "1February 2 1 day" instead of "1February 2 1 day", which is customary and has no specific reasons.

Language is universal and progressive. You can't frame it with strict rules, because it is widely spread, so how to express it is generally a conventional expression, which must conform to everyone's common expression habits, as long as everyone can understand it. Moreover, it is constantly developing and changing, adding many new words and changing many old words, which is why Xinhua Dictionary and Cihai must be updated regularly. Maybe everyone reads "December 21st" now, and everyone will read "December 21st" later!