It is the time when one regains their consciousness back, which is expressed with words “till you know what you are saying” in Quran 4:43. This has to be decided by the individual themselves.
يَا أَيُّهَا الَّذِينَ آمَنُواْ لاَ تَقْرَبُواْ الصَّلاَةَ وَأَنتُمْ سُكَارَى حَتَّىَ تَعْلَمُواْ مَا تَقُولُونَ وَلاَ جُنُبًا إِلاَّ عَابِرِي سَبِيلٍ حَتَّىَ تَغْتَسِلُواْ وَإِن كُنتُم مَّرْضَى أَوْ عَلَى سَفَرٍ أَوْ جَاء أَحَدٌ مِّنكُم مِّن الْغَآئِطِ أَوْ لاَمَسْتُمُ النِّسَاء فَلَمْ تَجِدُواْ مَاء فَتَيَمَّمُواْ صَعِيدًا طَيِّبًا فَامْسَحُواْ بِوُجُوهِكُمْ وَأَيْدِيكُمْ إِنَّ اللّهَ كَانَ عَفُوًّا غَفُوراً
Believers! Do not approach the place of the prayer when you are drunk till you know what you are saying nor when you are [ceremonially] unclean until you have bathed yourselves except if the intention is to pass through [the prayer place]. And if you are sick or on a journey, or when you have relieved yourselves or had intercourse with women and you find no water, take some clean mud and wipe your faces and your hands with it. Gracious is God and forgiving. (Quran 4:43)
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As a matter of Principle, All intoxicants are haram, even in small quantities:
يَاأَيُّهَا الَّذِينَ آمَنُوا إِنَّمَا الْخَمْرُ وَالْمَيْسِرُ وَالْأَنصَابُ وَالْأَزْلَامُ رِجْسٌ مِنْ عَمَلِ الشَّيْطَانِ فَاجْتَنِبُوهُ لَعَلَّكُمْ تُفْلِحُونَ
Believers, this liquor and gambling and stone altars and these divining arrows are abominations devised by Satan. Avoid them that you may succeed. (5:90)
And because of this prohibition, the criteria for acceptance of Salah and Prayers becomes very strict for the individual who does so after consuming such intoxicants.
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