Teach you the most direct way. The domestic market ends at 3 pm, and the external market takes Lenton as an example. In the evening when trading is active, it is divided into winter time and summer time. You take the indicator hour line of Rentong on the outer disk. Before the opening of the domestic market the next day, if you look at the market from yesterday 15 to today, you can calculate the ratio on the K-line, which is probably the range of high opening and low going today.