وَأَنذِرْهُمْ يَوْمَ ٱلْحَسْرَةِ إِذْ قُضِىَ ٱلْأَمْرُ وَهُمْ فِى غَفْلَةٍ وَهُمْ لَا يُؤْمِنُونَ
Waan th irhum yawma al h asrati i th qu d iya alamru wahum fee ghaflatin wahum l a yuminoon a hence, warn them of [the coming of] the Day of Regrets, when everything will have been decided - for as yet they are heedless, and they do not believe [in it].
 - Mohammad Asad
O Muhammad, forewarn them about the Day of intense regret when this matter will be decided, even though at present they are paying no heed and do not believe.
 - Muhammad Farooq-i-Azam Malik
And warn them 'O Prophet' of the Day of Regret, when all matters will be settled, while they are 'engrossed' in heedlessness and disbelief.
 - Mustafa Khattab
And warn them of the Day of anguish when the case hath been decided. Now they are in a state of carelessness, and they believe not.
 - Marmaduke Pickthall
But warn them of the Day of Distress when the matter will be determined: for (behold) they are negligent and they do not believe! 2491
 - Abdullah Yusuf Ali