It is not sinful to delay making up the fasts, but it is recommended to hasten in making them up; out of fear of death; because making up the fasts is required to be done at leisure, meaning it is an obligation that is broadly and absolutely free from time constraints. The time for its obligation is the time of performance, which is all days outside of Ramadan except for the six days; as Allah says: {So whoever among you is ill or on a journey, then a number of other days.} He commanded to make up the fasts without a specific time, so it is not permissible to restrict it to certain times except with evidence. Therefore, it is obligatory at any time without specification, and the option of specification is left to the person obligated. Whenever he initiates it, that time becomes obligatory, and if he does not initiate it, the obligation becomes restricted to the end of his life at a time when he is able to perform it before his death. There is no obligation for compensation due to the delay in making up the fasts; compensation is only required in cases of inability to fast, and here there is no inability as long as he is capable of making it up, so there is no meaning in requiring compensation.