Chinese idiom · 成语
一日千里
Meaning
Rapid progress; to advance swiftly.
Character by character
Origin and story
Philosophical analogyThe Qiu Shui (秋水) chapter of Zhuangzi (莊子) describes fine horses that can run a thousand li in a day. Yet, it adds, they are less useful than a wildcat at catching mice. Other comparisons likewise show that an impressive ability in one setting does not make something suitable for every task.
The phrase later came to emphasize the horses’ extraordinary speed, and then rapid progress in learning, technology, or other activity. The original discussion is not a recorded race or a tale about a named horse. A li is a Chinese distance unit, not an English mile, and the number functions here as an image of remarkable range.
Sources and further reading
In everyday life
有了稳定的练习时间，他的口语进步一日千里。
With regular time to practice, his speaking improved by leaps and bounds.
An emphatic description of rapid progress, not a literal measurement.