Chinese idiom · 成语
夜以继日
Meaning
Night follows day; relentless work without rest.
Character by character
Origin and story
philosophical accountThe Li Lou II chapter of the Mencius (孟子) praises the Duke of Zhou for studying the virtues of earlier rulers and seeking to put them into practice. When something did not fit, he continued thinking from day into night; when he found an answer, he sat waiting for dawn. The phrase describes that sustained attention to government and moral precedent.
The same wording also occurs in other early works, so the idiom should not be attached exclusively to a later Han biography. Its literal sequence is to let night carry on the activity of the day. Later usage describes work or other activity continuing around the clock, often with admiration, though the expression itself does not make exhaustion a requirement for doing worthwhile work.
Sources and further reading
In everyday life
为了恢复小区供水，维修人员轮班上岗，夜以继日地抢修。
Repair crews worked around the clock in shifts to restore the neighborhood's water supply.
For sustained day-and-night activity; a team working shifts fits naturally.