Obligation of succession when vowing to fast

A: If the person who made the vow to observe Sawm for one month did not specify how he would fast it, it is permissible for him to fast it successively or separately. However, if he intended it to be successive, or stated it, or determined a specific month, it is obligatory for him to fast it successively. This applies unless the month he specified is Rajab, because fasting for the month of Rajab is Makruh (disliked), in which case he has to offer a Kaffarah (expiation) for breaking an oath.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family and Companions.