"This day," meaning: in the Hereafter, "every soul shall be recompensed for what it earned; there is no injustice today. Verily, Allah is swift in reckoning." I heard some of the Kufans say: He shall finish the reckoning of the creatures in the span of half a day of the days of this world, once He begins the reckoning of the creatures and their presentation.
﴿الْيَوْم﴾ يَعْنِي: فِي الْآخِرَة ﴿تُجْزَى كُلُّ نَفْسٍ بِمَا كَسَبَتْ لَا ظُلْمَ الْيَوْمَ إِنَّ اللَّهَ سَرِيعُ الْحِسَابِ﴾ سَمِعْتُ بَعْضَ الْكُوفِيِّينَ يَقُولُ: يَفْرَغُ من حِسَاب الْخَلَائق فِي مِقْدَار نِصْفِ يَوْمٍ مِنْ أَيَّامِ الدُّنْيَا إِذا أَخذ فِي حِسَاب الْخَلَائق وعرضهم.