Hadith 625B3

وَسُئِلَ عَمَّنْ أَسْلَمَ فِي آخِرِ يَوْمٍ مِنْ رَمَضَانَ ، هَلْ عَلَيْهِ قَضَاءُ رَمَضَانَ كُلِّهِ أَوْ يَجِبُ عَلَيْهِ قَضَاءُ الْيَوْمِ الَّذِي أَسْلَمَ فِيهِ ؟ فَقَالَ : لَيْسَ عَلَيْهِ قَضَاءُ مَا مَضَى وَإِنَّمَا يَسْتَأْنِفُ الصِّيَامَ فِيمَا يُسْتَقْبَلُ وَأَحَبُّ إِلَيَّ أَنْ يَقْضِيَ الْيَوْمَ الَّذِي أَسْلَمَ فِيهِ
Imam Malik, may Allah have mercy on him, was asked: If a person becomes Muslim in the evening with some days of Ramadan remaining, is it obligatory for him to make up the entire Ramadan or just the day on which he became Muslim? Imam Malik, may Allah have mercy on him, replied: It is not obligatory for him to make up the previous fasts, rather he should fast from then onwards, and if he also makes up the fast of the day on which he became Muslim, then that is better.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب الصيام / 625B3
Hadith Takhrij «شركة الحروف نمبر: 629، فواد عبدالباقي نمبر: 18 - كِتَابُ الصِّيَامِ-ح: 49»