Muhammad ibn Yaqub, from a number of our companions, from Sahl ibn Ziyad, from al-Hasan ibn Mahbub, from Ali ibn Riab, from Samaah, who said: I (narrator) asked Abu Abdillah عليه السلام, peace be upon him, about ‘the woman with irregular bleeding (mustahadah).’ Imam عليه السلام said: “She fasts the month of Ramadan except for the days in which she used to menstruate, then she makes them up afterwards.”