And the Verse further states, “… but no one knows its interpretation but Allah. …”

Less than a century ago, only God possessed knowledge about television and space satellites, for example. He revealed this knowledge at the predetermined time. Similarly, God has revealed the time appointed for the end of this world.
[72:26] He is the Knower of the future; He does not reveal the future to anyone.
[72:27] Only to a messenger that He chooses, does He reveal from the past and the future, specific news

[20:15] “The Hour (end of the world) is surely coming; I will keep it almost hidden, for each soul must be paid for its works.

20:15, where God informs us that the end of the world will not remain hidden, has a very important number. Of all the verses in the Quran God chose verse 20:15 to give us this information. The number 2015 is a composite number . The index of the composite number 2015 is 1709.
As you can see the year of the end of the world is pointed to in 20:15 indirectly from the moment the Quran was revealed

[72:28] This is to ascertain that they have delivered their Lord’s messages. He is fully aware of what they have. He has counted the numbers of all things.

Also The birth of Jesus set as a marker for the end of the world

[43:61] He is to serve as a marker for knowing the end of the world, so you can no longer harbor any doubt about it. You shall follow Me; this is the right path.

We know that between the birth of Jesus and the birth of Muhammad there is 570 years.

This number of years between the birth of Jesus and the birth of Muhammad, which is 570, confirms the calculations of the end of the world.

The world will end in the year 2280 A.D. , which corresponds to the year 1710 A.H. Both 2280 and 1710

The number of years between the birth of Jesus and Muhammad (570) is the same as the number of years between the end of the world in Solar calendar (2280) which is connected to the birth of Jesus, and the end of the world in Islamic Lunar calendar (1710) which is connected to the hijra (immigration to Medina) of Muhammad (and not his birth).
birth of Jesus (0) - Birth of Muhammed (570) = 570 years
End of world A.D (2280) - end of world A.H. (1710) = 570 years

Allah only knows the truth, May Allah Guide us to understand the Quran

The seven pairs mentioned in Verse 15:87 are the 14 Quranic Initials. The total gematrical value of these profound pillars of the Quran’s miracle pinpoints the year of the end of the world.

Total Gematrical Value of “The Seven Pairs” of Quranic Initials
Quranic
Initial Gematrical Value
1. Q 100
2. N 50
3. S (Saad) 90
4. H.M. 48
5. Y.S. 70
6. T.H. 14
7. T.S. 69
8. A.L.M. 71
9. A.L.R. 231
10. T.S.M. 109
11. `A.S.Q. 230
12. A.L.M.S. 161
13. A.L.M.R. 271
14. K.H.Y.`A.S. 195

Total = 1709

According to 15:87, the world will survive for 1709 lunar years from the time this prophecy is stated in the Quran.(Allah only know the correct meaning)

While Hadith is forbidden as a source of religious teachings , it can be a useful source of history. We can derive a lot of information about historical events and local customs and traditions during the early centuries of Islam. The books of Hadith indicate that the Quranic Initials were believed to determine the life span of the Muslim Ummah.The classic exegesis by Al-Baydaawy cites the following historical event as a possible explanation of the Quranic Initials. The same event is detailed in Al-Suyooty’s ITQAAN, First Printing, 1318 AH, Vol 2, Page 10:

The Jews of Medina went to the Prophet and said, “Your Quran is initialed with A.L.M., and these Initials determine the life span of your religion. Since `A’ is 1, `L’ is 30, and `M’ is 40, this means that your religion will survive only 71 years.” Muhammad said, “We also have A.L.M.S.” They said, “The `A’ is 1, the `L’ is 30, the `M’ is 40, and the `S’ is 90. This adds up to 161. Do you have anything else?” The Prophet said, “Yes, A.L.M.R.” They said,
“This is longer and heavier; the `A’ is 1, `L’ is 30, `M’ is 40,
and `R’ is 200, making the total 271.” They finally gave up,
saying, “We do not know how many of these Initials he was given!”
[Al-Suyuty’s Famous Reference ITQAAN]

Although this narration is well known, many scholars have been reluctant to accept the unmistakable connection between the Quranic initials and the end of the world. They could not bring themselves to deal with this subject for the simple reason that the calculation makes the end of the world, and judgment, a reality.

Mohammad Shafi responds:
When the All-knowing Allah has Himself stated that His design is to keep the Hour a secret (20.15) and that its knowledge is only with Him (33.63), how can you depend on the error-prone ahaadeeth to negate divine statements?