Is it obligatory to feed the poor for delayed Ramadan fasts only during the month of Ramadan, or can they be fed in any month?

If a wife has not made up the days of the previous Ramadan (definition), despite being able to, until the next Ramadan begins, she must pay an expiation for delaying the make-up (qada’). This expiation is one mudd of food for each day, from the staple food of the local people, and it should be given to the poor. It is permissible to give the expiation at any time, but it is better to do so before making up the fasts.