Question 26: A woman used to perform Sawm (Fast) during the six days of Shawwaal every year. One year, she gave birth at the beginning of Ramadaan and did not become ritually purified until after the end of Ramadaan. She then made up for the days of Sawm she had missed. Does she also have to make up for the six days of Shawwaal after making up for Ramadaan days, even if it is not still Shawwaal, or does she have to make up for Ramadaan only? Is it obligatory to always fast the six days of Shawwaal?
Answer: Performing Sawm for six days of Shawwaal is a Sunnah (supererogatory act of worship following the example of the Prophet), not a Fareedah (obligatory act), according to the saying of the Prophet (peace be upon him): Anyone who fasts Ramadaan and then follows it with six days of Shawwaal it is as if they fasted the whole year. (Related by Imaam Muslim in his Saheeh [Authentic Book Hadeeth]) This Hadeeth is evidence that there is nothing wrong in fasting these days consecutively or separately, based on its general wording... read more here.