Hadith 153
'Umar bin Al-Khattab (May Allah be pleased with him) reported:
وعن عمر بن الخطاب رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم: " من نام عن حزبه من الليل، أو عن شيء منه فقرأه ما بين صلاة الفجر وصلاة الظهر، كتب له كأنما قرأه من الليل" ((رواه مسلم)).
Messenger of Allah (ﷺ) said, "Should anyone fall asleep at night and fail to recite his portion of the Qur'an, or a part of it, if he recites it between the Fajr prayer and the Zuhr prayer, it will be recorded for him as though he had recited it during the night". [Muslim].
In plain words
If someone sleeps through their usual night recitation, reciting it between dawn and midday counts as if done at night. Allah's mercy makes room to make up a missed good habit.
Reference : Riyad as-Salihin 153 In-book reference : Introduction, Hadith 153