When does a woman begin her prayers and fasting if her postpartum bleeding (nifas) exceeds forty days, specifically on the forty-first day, taking into account the opinion that the maximum duration of nifas is forty days?

If the maximum duration of nifas (postpartum bleeding) is forty days, then the period ends at the same hour on the forty-first day as when the blood first appeared. So, if the blood appeared at 4:00 PM on the first day of the month, the forty days would end at 4:00 PM on the eleventh day of the following month. At that point, she should perform ghusl (ritual bath) and pray, unless that day coincides with her regular menstrual period, in which case she should consider it menstruation.