It wasnarrated that Abu Salamah said:
"I heard 'Aishah say: 'I usedto owe fasts from the month of Ramadan, and I would not make them upfor until Sha'ban came.'" (FR)
English reference (FR): Vol. 1, Book 7, Hadith 1669 (FR)
Arabic reference (FR): Book 7, Hadith 1738 (FR)