Answered by Shaykh Hamza Karamali, SunniPath Academy Teacher
If one is performing an optional fast (such as the fasts of Shawwal) and breaks the fast during the day (whether accidentally or intentionally), is it obligatory to make up the fast later on? Also, is it permissible to break an optional fast on purpose?
In the Name of Allah, Most Merciful and Compassionate
Is it permissible to break a supererogatory fast?
According to the Shafi’i school, it is not forbidden (haram) to break one’s supererogatory fast, although it is disliked (makruh) if done without an excuse.
Two situations in which one is considered “excused” (and thus exempted from the karahah mentioned above) is when one is a guest and it weighs heavily on one’s host if one does not eat, or when one is a host trying to feed one’s guest and it weighs heavily on one’s guest to eat alone. In both these cases, breaking one’s nafl fast would actually be recommended.
(Fath al-‘Allam, 4.125)
Does one have to make up such fasts?
It is not obligatory to make up supererogatory fasts that one has broken, regardless of whether they were broken with an excuse or without one. However, since other schools (such as the Hanafi) hold that such fasts are necessary to make up, it would be recommended to make them up in the Shafi’i school as well.
(Fath al-‘Allam, 4.125)
Note: Generally speaking, unintentionally doing something that would normally nullify the fast does not nullify the fast in the Shafi’i school, as explained in the fasting leaflet that was recently posted to the list.[1]
And Allah knows best.
Hamza Karamali and Mostafa Azzam.
[1] An exception to this general rule is if the unintentional commission of a nullifier occurred as a result of doing something uncalled for, such as exaggerating in rinsing out one’s mouth during wudu. One can refer to the fasting leaflet for more examples.