Man Lā Yaḥḍuruh al-Faqīh
Hadith 4362006 - وَ رَوَى مَنْصُورُ بْنُ حَازِمٍ عَنْهُ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: فِي رَجُلٍ صَامَ فِي ظِهَارٍ شَعْبَانَ ثُمَّ أَدْرَكَهُ شَهْرُ رَمَضَانَ قَالَ «يَصُومُ شَهْرَ رَمَضَانَ ثُمَّ يَسْتَأْنِفُ اَلصَّوْمَ وَ إِنْ هُوَ صَامَ فِي اَلظِّهَارِ فَزَادَ فِي اَلنِّصْفِ يَوْماً قَضَى بَقِيَّتَهُ».
Hadith.2006 - Mansur ibn Hazim narrated from Abu Abdullah (as) regarding a man who was fasting as expiation (for zihar) during Sha’ban and then Month of Ramadan began.
Imam (as) said: "He should fast the Month of Ramadan and then resume the expiation fast. However, if he was fasting for expiation and completed half a day more than the midpoint (of the fast), he can simply complete the remaining days."