The lajnah (Permanent Committee For Scholarly Research And Ifta’) were asked:

Question:

“Should the voluntary Sawm (Fast) of the six days of Shawwal be observed directly after Ramadan, following the day of `Eid-ul-Fitr (the Festival of Breaking the Fast), or is it permissible to start observing it several days after `Eid-ul-Fitr, during the month of Shawwal?”

Answer:

“It is not necessary to observe this Sawm directly after `Eid-ul-Fitr. It is permissible to start observing it one or more days afterwards. The six days can be observed either consecutively or non-consecutively during the month of Shawwal, whichever is easier. This matter is open to choice, as this Sawm is Sunnah and not Faridah (obligatory act).

May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.
Permanent Committee for Scholarly Research and Ifta’” End quote. [Reference]

Mentioned by

AbdulFattaah Bin Uthman
Abu Fajr