Al-A'raf - 7:187

يَسْأَلُونَكَ عَنِ السَّاعَةِ أَيَّانَ مُرْسَاهَا قُلْ إِنَّمَا عِلْمُهَا عِندَ رَبِّي لاَ يُجَلِّيهَا لِوَقْتِهَا إِلاَّ هُوَ ثَقُلَتْ فِي السَّمَاوَاتِ وَالأَرْضِ لاَ تَأْتِيكُمْ إِلاَّ بَغْتَةً يَسْأَلُونَكَ كَأَنَّكَ حَفِيٌّ عَنْهَا قُلْ إِنَّمَا عِلْمُهَا عِندَ اللّهِ وَلَـكِنَّ أَكْثَرَ النَّاسِ لاَ يَعْلَمُونَ
[7:187]
They ask you about the hour, when will be its taking place? Say: The knowledge of it is only with my Lord; none but He shall manifest it at its time; it will be momentous in the heavens and the earth; it will not come on you but of a sudden. They ask you as if you were solicitous about it. Say: Its knowledge is only with Allah, but most people do not know.
They ask thee about the (final) Hour - when will be its appointed time? Say: "The knowledge thereof is with my Lord (alone): None but He can reveal as to when it will occur. Heavy were its burden through the heavens and the earth. Only, all of a sudden will it come to you." They ask thee as if thou Wert eager in search thereof: Say: "The knowledge thereof is with Allah (alone), but most men know not."
They ask thee of the (destined) Hour, when will it come to port. Say: Knowledge thereof is with my Lord only. He alone will manifest it at its proper time. It is heavy in the heavens and the earth. It cometh not to you save unawares. They question thee as if thou couldst be well informed thereof. Say: Knowledge thereof is with Allah only, but most of mankind know not.