“Whoever fasts Ramadan and follows it with six days from Shawwal, it is as if they fasted the entire year.” [Muslim, Thirmidhee, Abu Dawud]
It is highly recommended to fast six days of the month of Shawwal.
How to Fast in Shawwal after Ramadan/Eid al-Fitr
It is best to fast six days consecutively. It is also permitted to fast these six days separately/ non-consecutively throughout the month, after Eid al-Fitr, during Shawwal.
However, delaying the fast can result in one becoming lazy and not fasting, so it is best to fulfill the sunnah by fasting six days consecutively immediately after Eid al-Fitr in Shawwal. However, neither is disliked and both consecutive and non-consecutive days will fulfill the sunnah, inshallah. If you fear that you will not be able to fulfill the recommendation due to laziness or forgetfulness, then you should hasten to fast the six days consecutively immediately after Eid al-Fitr.
Reward for Fasting Six Days of Shawwal after Ramadan
The reward is equivalent to having fasted for the entire year. “Whoever fasts Ramadan and follows it with six days from Shawwal, it is as if they fasted the entire year.” [Muslim, Thirmidhee, Abu Dawud]
Also, a good deed in Islam is rewarded 10 times, so fasting 30 days in Ramadan and 6 days more days after Eid al-Fitr during Shawwāl is equivalent to fasting the whole year in terms of reward.
Can I Fast on Eid al-Fitr?
No. However, you may start your six days of fasting beginning the day after Eid al-Fitr, in the month of Shawwal.
When is the First Day of Shawwal?
The first day of Shawwāl is Eid al-Fitr.
Fasting Six Days of Shawwal after Ramadan is Like Fasting the Entire Year
If you are able to fulfill this sunnah, you should take advantage of this opportunity of acquiring such an enormous reward.