It is narrated from Hazrat Aisha (may Allah be pleased with her) that I used to make up my missed fasts of Ramadan only in the month of Sha'ban until the Prophet (peace and blessings be upon him) passed away.
Hadith Referenceمسند احمد / مسند النساء / 24999
Hadith Gradingحکم دارالسلام:حديث صحيح، واختلف فى سماع عبدالله من عائشة، خ: 1950، م: 1146