The World Federation One Stop Fiqh

Ruling 1675

If a person is negligent in keeping qaḍāʾfasts until the time [before the next Ramadan] becomes short, and in the shortage of time a legitimate excuse arises, he must make them up; and based on obligatory precaution, he must also give one muddof food to a poor person for each day. The same applies if after the excuse expires he decides to make up his fasts but before he does so, a legitimate excuse arises in the short time [remaining before Ramadan].