Question: Please tell me which months we may fast to make up for the missed days in Ramadaan. What are the pillars of faith? How can a Muslim be sinless? I have a brother who did not fast the last few days of Ramadaan (namely 25, 26, 27, 28, 29 and 30). He wanted to make up for them in the month of Rajab. What is your opinion about this?
Answer: Your brother must make up for the days in which he broke his fast during Ramadaan. It is a priority that he starts to make up for them after the end of Ramadaan unless there is a valid excuse. It is permissible for your brother to make up for his missed days of fast during the month of Rajab… read more here.