Changing the calculation method for the waiting period from months to menstrual cycles: The scholars are in consensus that if the wife who is too young to have menstruation and the wife who is past the age of childbearing start their waiting period according to the method of months, but then they had their menstruation before the end of the months, the calculation of their waiting period will change from the method of months to the method of menstrual cycles. This consensus [230] However, they differed on whether she needs to count what she observed of the past months as menstrual cycles or not. has been transmitted by Ibn al-Munthir, Ibn Hazm, al-’Amraanee, al-Qurtubee, and al-Shirbeenee.
2. Changing the calculation method for the waiting period from menstrual cycles to months: The scholars are in consensus that if the wife who is past the age of childbearing started her waiting period according to the method of menstrual cycles, but then her menstruation ended before the end of the menstrual cycles, the calculation of her waiting period will change from the method of menstrual cycles to the method of months. This consensus has been transmitted by Ibn Al-’Arabee and Al-Qurtubee.
3. Changing the calculation method for the waiting period from menstrual cycles and months to the time of delivery: The four Madhabs [231] Some Hanafi scholars made an exception for the wife whose husband is a minor boy. As such, if she gives birth after more than half a year from his death, then she needs to observe her waiting period by months. agree that if the divorcee is found to be pregnant during her waiting period, which has been calculated according to the method of months or menstrual cycles, the calculation method will change, and her waiting period will end upon giving birth to the child.
4.  Changing the waiting period from a divorcee’s waiting period to a widow’s waiting period. The scholars are in consensus that in the event where the divorce is revocable, and the husband dies before the expiry of the waiting period, then the waiting period of the wife changes from the waiting period of divorce to the waiting period of death. This consensus has been transmitted by Ibn al-Munthir, Ibn Rushd, Ibn Qudaamah, and Ibn Taymiyyah.