وَلِكُلِّ أُمَّةٍ أَجَلٌ ۖ فَإِذَا جَآءَ أَجَلُهُمْ لَا يَسْتَأْخِرُونَ سَاعَةً ۖ وَلَا يَسْتَقْدِمُونَ
Asad Quran Translation
And for all people a term has been set:25
and when [the end of] their term approaches, they can neither delay it by a single moment,26
nor can they hasten it.
Lit., "for every community (ummah) there is a term": i.e., all people have a life-term decreed by God, during which they are at liberty to accept or to reject the guidance offered them through revelation. The word ummah often denotes "living beings" - in this context, "people".
In Arabic usage, the term sa'ah (lit., "hour") signifies not merely the astronomical hour - i.e., the twenty-fourth part of a mean solar day - but also "time" in an absolute sense, or any fraction of it, whether large or small. In the above context, it has obviously been used in the sense of "a least fraction of time" or "a single moment".
Malik Quran Translation
For every nation there is a fixed term, when their term expires, it can neither be delayed for a moment nor can it be made to come early."
Yusuf Ali Quran Translation
To every people is a term appointed: when their term is reached not an hour can they cause delay nor (an hour) can they advance (it in anticipation). 1017
People: ummat. I do not know whether "generation" would not be more appropriate here. If so, it would refer to the Time-Spirit, for it affects a whole number of people living contemporaneously, and while we deal grammatically with a group, we really have in mind the individuals composing the group. Anyway, the lesson is what is suggested in the following verses. There is only a limited time for an individual or for a group of people. If they do not make good during that time of probation, the chance is lost, and it cannot come again. We cannot retard or advance the march of time by a single hour or minute. ("Hour" in the text expresses an indefinite but short period of time).
Mustafa Khattab Quran Translation
For each community there is an appointed term. When their time arrives, they can neither delay it for a moment, nor could they advance it.
Piktal Quran Translation
And every nation hath its term, and when its term cometh, they cannot put it off an hour nor yet advance (it).
Walikulli ommatin ajalun faitha jaa ajaluhum la yastakhiroona saAAatan wala yastaqdimoona