﴿ وَلِلَّهِ غَيْبُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ وَمَآ أَمْرُ ٱلسَّاعَةِ إِلَّا كَلَمْحِ ٱلْبَصَرِ أَوْ هُوَ أَقْرَبُ ۚ إِنَّ ٱللَّهَ عَلَىٰ كُلِّ شَىْءٍۢ قَدِيرٌۭ ﴾

“And, God's [alone] is the knowledge of the hidden reality of the heavens and the earth. And so, the advent of the Last Hour will but manifest itself [in a single moment,] like the twinkling of an eye, or closer still: for, behold, God has the power to will anything.”

Please check ayah 16:79 for complete tafsir.