The word(s) "day" appears 704 time(s) in 579 verse(s) in Quran in Mohsin Khan translation.

(401) And he ['Îsa (Jesus), son of Maryam (Mary)] shall be a known sign for (the coming of) the Hour (day of Resurrection) [i.e. 'Isa's (Jesus) descent on the earth]. Therefore have no doubt concerning it (i.e. the day of Resurrection). And follow Me (Allah) (i.e. be obedient to Allah and do what He orders you to do, O mankind)! This is the Straight Path (of Islamic Monotheism, leading to Allah and to His Paradise).

(402) But the sects from among themselves differed. So woe to those who do wrong [by ascribing things to 'Îsa (Jesus) that are not true] from the torment of a painful day (i.e. the day of Resurrection)!

(403) Friends on that day will be foes one to another except Al-Muttaqun (the pious. See V.2:2).

(404) (It will be said to the true believers of Islamic Monotheism): My worshippers! No fear shall be on you this day, nor shall you grieve,

(405) So leave them (alone) to speak nonsense and play until they meet the day of theirs which they have been promised.

(406) Then wait you for the day when the sky will bring forth a visible smoke,

(407) On the day when We shall seize you with the greatest seizure (punishment). Verily, We will exact retribution.

(408) Verily, the day of Judgement (when Allah will judge between the creatures) is the time appointed for all of them -

(409) The day when a Maula (a near relative) cannot avail a Maula (a near relative) in aught, and no help can they receive,

(410) And in the alternation of night and day, and the provision (rain) that Allah sends down from the sky, and revives therewith the earth after its death, and in the turning about of the winds (i.e. sometimes towards the east or north, and sometimes towards the south or west sometimes bringing glad tidings of rain etc., and sometimes bringing the torment), are signs for a people who understand.