question #1 Sahih al-Bukhari 1950, Book 30, Hadith 57 : What are the permissible reasons for delaying the missed fasts of Ramadan?

Sometimes I missed some days of Ramadan, but could not fast in lieu of them except in the month of
Sha’ban.” Said Yahya, a sub-narrator, “She used to be busy serving the Prophet (ﷺ) .”