Yawm is interpreted in four ways:
1. Yawm is used in the sense of each of the six days in which the Mighty and Majestic Allah created the world; as in the following verses:
Say, "Do you indeed disbelieve in He who created the earth in two days?" (Fussilat 41:9)
And He determined therein its sustenance in four days. (Fussilat 41:10)
And He completed them as seven heavens in two days. (Fussilat 41:12)
Thus, in this way, the six days are completed.
It is Allah who created the heavens and the earth and whatever is between them in six days {these days, in the sight of Allah, are like the days of the world}. (al-Sajda 32:4)
Indeed, a day with your Lord is like a thousand years of those which you count. (al-Hajj 22:47)
2. Yawm is used in the sense of the days of the world; as in the following verse:
He arranges [each] matter from the heaven to the earth; then it will ascend to Him in a day {that is, the measure of Gabriel's descent} the extent of which is a thousand years of those which you count {in a day of the days of the world}. (al-Sajda 32:5)
3. Yawm is used in the sense of the Day of Resurrection (the Hereafter); as in the following verses:
That Day {that is, in the Hereafter (on the Day of Resurrection)} no soul will be wronged at all. (Ya-Sin 36:54)
Indeed, that Day {that is, in the Hereafter (on the Day of Resurrection)} the companions of Paradise... (Ya-Sin 36:55)
That Day {that is, in the Hereafter (on the Day of Resurrection)} every soul will be recompensed for what it earned. (al-Mu'min 40:17)
There are many similar statements.
That Day {(that is, in the Hereafter)} We will seal over their mouths... (Ya-Sin 36:65)
4. Yawm is used in the sense of ḥīn [time / moment]; as in the following verses:
Peace be upon him the day {that is, the time} he was born, the day {that is, the time} he dies, and the day {that is, the time} he is raised alive. (Maryam 19:15)
{Jesus said:} "Peace is on me the day {that is, the time} I was born, the day {that is, the time} I will die, and the day {that is, the time} I am raised alive." (Maryam 19:33)
On the day {that is, at the time} you travel and the day {that is, at the time} you settle... (al-Nahl 16:80)
And give its due on the day of its harvest {that is, at the time when you harvest [gather, collect] your crops}! (al-An'am 6:141)