"The Messenger of Allah said: The month may be twenty-nine days or it may be thirty. When you see it, then stop fasting, and it is obscured from you (too cloudy), then complete the count."'
قَالَ رَسُولُ اللَّهِ ﷺ الشَّهْرُ يَكُونُ تِسْعَةً وَعِشْرِينَ وَيَكُونُ ثَلاَثِينَ فَإِذَا رَأَيْتُمُوهُ فَصُومُوا وَإِذَا رَأَيْتُمُوهُ فَأَفْطِرُوا فَإِنْ غُمَّ عَلَيْكُمْ فَأَكْمِلُوا الْعِدَّةَ