Probably NO one lacks knowledge about time zones and DST more than the Chinese which has only one time zone (Beijing Time) for the entire country which spans 5 time zone bands. I you live in western China the "crack of dawn" has you up and at 'em at 11AM! The concept of DST or individual states setting their own time is not inherent knowledge there. They need to be told that a 'DST Enabled' check box has to be added to time zone selection as well as week, day and month for DST start and end, i.e., '2nd Sunday March' as it may differ by country or change at some point.
If software development has to be kept in China for some reason, then at least a comprehensive spec needs to be presented to the team IN PERSON. 20 years ago, when I first sent a software spec to the Chinese developers (actually in Taiwan) for a telephone call routing device that I designed, what I got back was virtually useless. I went there and had the development team in a room where I gave a 'chalk talk' going over every detail of the spec and explaining why and how the US telephone system worked. The translator was good and they video taped the whole meeting and took photos of everything that I did on the whiteboard while taking copious notes in Chinese. The result was far superior with only some minor tweaks needed that were made in days - not weeks. I don't know if Authinx is doing this but they will continue to be frustrated if they're not.
Funny story: When my wife (who can speak Chinese) and I went to the lab there for final pre-production acceptance testing, we discovered a major flaw that made the 10,000 chips they had produced without approval worthless. While they huddled a few feet away discussing the situation in Chinese, my wife whispered, "they're going to tell you 'this will take 6 weeks to correct' but they really can do it in 3." Sure enough they came back and said it would take 6 weeks and I told them NO!, they had to do it in 3. They had forgotten that my wife could understand them and had the biggest 'Oh crap' look on their faces when they realized what had just happened!