Because China's expression in ancient times was artistic, in order to capture the artistic conception of "endless stream", the "stream" of "flowing water" was used to simply express the different fortune of each year before the year.
So, when someone says, "Alas, the time next year is really bad …", what he means is "the luck next year is really bad".
In addition, numerology often uses terms such as "Ryutsuki" and "fleeting time", which, like fleeting time, actually represents the monthly or daily changes of fortune.