The word(s) "hour" appears 56 time(s) in 47 verse(s) in Quran in Abdullah Yusuf Ali translation.

(21) Those who reject Faith will not cease to be in doubt concerning (Revelation) until the hour (of Judgment) comes suddenly upon them, or there comes to them the Penalty of a Day of Disaster.

(22) Nay they deny the hour (of the judgment to come): but We have prepared a blazing fire for such as deny the hour:

(23) On the Day that the hour will be established, the guilty will be struck dumb with despair.

(24) On the Day that the hour will be established,- that Day shall (all men) be sorted out.

(25) On the Day that the hour (of Reckoning) will be established, the transgressors will swear that they tarried not but an hour: thus were they used to being deluded!

(26) Verily the knowledge of the hour is with Allah (alone). It is He Who sends down rain, and He Who knows what is in the wombs. Nor does any one know what it is that he will earn on the morrow: Nor does any one know in what land he is to die. Verily with Allah is full knowledge and He is acquainted (with all things).

(27) Men ask thee concerning the hour: Say, "The knowledge thereof is with Allah (alone)": and what will make thee understand?- perchance the hour is nigh!

(28) The Unbelievers say, "Never to us will come the hour": Say, "Nay! but most surely, by my Lord, it will come upon you;- by Him Who knows the unseen,- from Whom is not hidden the least little atom in the heavens or on earth: Nor is there anything less than that, or greater, but is in the Record Perspicuous:

(29) Say: "The appointment to you is for a Day, which ye cannot put back for an hour nor put forward."

(30) Is one who worships devoutly during the hour of the night prostrating himself or standing (in adoration), who takes heed of the Hereafter, and who places his hope in the Mercy of his Lord - (like one who does not)? Say: "Are those equal, those who know and those who do not know? It is those who are endued with understanding that receive admonition.