Each trader sets his own opening and closing time, which is not uniform all over the world. Frankly speaking, a trader can open the market and start trading at any time when he likes, but there are some rules in the industry, which are commonly known as closing time. Generally, the closing time is based on the closing time of the US Eastern Time (West Fifth District), and it usually closes at around 5 am Beijing time (daylight saving time). Maybe in advance, maybe later, but generally not too far. It's all done in an hour. As for opening, not necessarily, it is usually open around 5 am on Monday, Beijing time.
Due to the uneven qualifications of domestic distributors, it is difficult for investors to distinguish between true and false, and they simply refer to factors such as spreads and remittance convenience. Therefore, the details of such traders vary greatly, including many intervention factors and no written and systematic explanation. Big traders have detailed explanations for these details.