Analyze the words in the title: the time to borrow books in the title is Wednesday, and reading from tomorrow means that the second day of borrowing books (Wednesday) is Thursday. Return the book two days after reading it, that is to say, the reading time is Thursday and Friday, and return the book two days later means returning it after reading it (Friday), that is, Saturday.

According to the above analysis, it can also be solved by mathematical formula. The mathematical expression of the topic is: 3+2+ 1=6. 3 is the start time, 2 is the reading time and 1 is the return time.

Extended data:

This week's source:

Through the observation of the moon's profit and loss, the ancients found that it takes seven days from half moon to full moon and from full moon to half moon respectively, and it takes seven days to disappear from half moon to half moon. So people divide a month into four weeks and take seven days as a cycle.

Zhou originated in Babylon as a time period. At present, the system of seven days a week, which is widely practiced all over the world, was first formulated by the Roman emperor Constantine the Great. On March 7th, 32 1 year, he officially announced a seven-day week, and this system has been in use ever since. In China, when Christianity spread in China in the late Ming and early Qing Dynasties, Zhou gradually became known. After the use of the Gregorian calendar was stipulated in the Republic of China, the week gradually became popular.

Baidu encyclopedia-Zhou