Explaining the Day of Decision and what occurs during it

Allah says about the Day of Decision -- and it is the Day of Judgement -- that it is at a fixed time, with a set appointment. Its time cannot be added to or decreased. No one knows its exact time except Allah. This is as Allah says,

وَمَا نُؤَخِّرُهُ إِلاَّ لاًّجَلٍ مَّعْدُودٍ

لَّابِثِينَ فِيهَا أَحْقَابًا (who will be abiding in it for ages....78:23). The word labithin is the plural of labith which means 'one who abides'. The word ahqab is the plural of hiqbah and means 'ages or a long time'. Scholars differ on the exact length or specific amount of time meant by this word. Ibn Jarir has recorded that Sayyidna ` Ali ؓ states that hiqbah is eighty years, and the year constitutes twelve months, and every month comprises thirty days, and each day is equivalent to one thousand years, thus one hiqbah totalling about twenty million and eighty-eight hundred thousand years . Sayyidna Abu Hurairah, ` Abdullah Ibn ` Umar, Ibn ` Abbas ؓ and others say that one hiqbah is seventy years instead of eighty years. The rest of the calculation remains the same. [ Ibn Kathir ]. In Musnad of Bazzar, Sayyidna ` Abdullah Ibn ` Umar ؓ traces the following Hadith to the Holy Prophet ﷺ :

لا یخرج احدکم من النّار حتّٰی یمکث فیہ احقاباً ، والحقب بضع و ثمانون سنۃ، کل سنۃ ثلثمایٔۃ وستّون یوما ممّا یعدّون