Estimation of deeds is for Allaah alone

Question: If someone misses ten days of fasting in Ramadaan due to a Shar‘ee (Islaamic legal) excuse, and then fasts the six days of Shawwaal after Ramadaan without making up for the missed days of Ramadaan, will they attain the Thawaab (reward from Allaah) promised for fasting the whole month of Ramadaan then following it with fasting the six days of Shawwaal? Will it be as if they have fasted for the whole year? Guide us, and may Allaah reward you with the best.

Answer: Determining the rewards of the deeds performed by a servant of Allaah is the special domain of Allaah (Glorified and Exalted be He). If a servant seeks the reward of Allaah (Glorified and Exalted be He), and exerts themselves in their obedience to Allaah, their reward will not be lost. Allaah (Exalted be He) says: …certainly We shall not make the reward of anyone who does his (righteous) deeds in the most perfect manner to be lost. Anyone who still has missed days of Ramadaan which they need to make up for should first fast them, and then fast the six days of Shawwaal. Following the Sawm (Fast) of Ramadaan with six days of Shawwal will not be fulfilled unless one has first completed the Sawm of Ramadaan... read more here.

We hear that anyone who fasts regularly should not give up doing so, is it correct?

Question: If a person, who is used to fasting the six days of Shawwaal regularly, becomes sick, hindered, or feels lazy to fast them in one of the years, is this a sin? We hear that anyone who fasts them regularly should not give up doing so.

Answer: Fasting the Six Days of Shawwaal after the day of `Eed-ul-Fitr (the Festival of Breaking the Fast) is an act of Sunnah (whatever is reported from the Prophet). It is not obligatory upon anyone who fasts them once or more to continually fast them. It is not a sin to abstain from fasting them... read more here.