Voluntary Fasting: Recommended Sunnah Fasts

The Place of Voluntary Fasting in Islam

Fasting outside of Ramadan is one of the most praised acts of voluntary worship in Islam. The Prophet (PBUH) said: "Fasting is a shield" (Bukhari and Muslim) — a shield against sin and hellfire. Voluntary fasts provide an opportunity to draw closer to Allah, accumulate immense reward, and discipline the soul beyond the compulsory minimum. The scholars of all four madhabs agree that voluntary fasting is a highly recommended Sunnah with numerous categories, each carrying its own virtues.

Six Days of Shawwal

One of the most strongly emphasized voluntary fasts follows immediately after Ramadan. Abu Ayyub al-Ansari (RA) narrated that the Prophet (PBUH) said: "Whoever fasts Ramadan and then follows it with six days of Shawwal, it is as if he fasted the entire year" (Muslim). Scholars explain this mathematically: Ramadan is equivalent to ten months of reward (each day multiplied by ten), and six days of Shawwal equal two months, completing the full year. These six days may be fasted consecutively or spread throughout the month of Shawwal, though consecutive fasting after Eid is recommended by some scholars.

Mondays and Thursdays

The Prophet (PBUH) regularly fasted on Mondays and Thursdays. When asked about Monday fasting, he said: "That is the day I was born and the day revelation first came to me" (Muslim). He also said: "Deeds are presented [to Allah] on Monday and Thursday, and I love that my deeds be presented while I am fasting" (Tirmidhi). Aisha (RA) confirmed that the Prophet (PBUH) was keen to fast on these two days. Many scholars consider these among the most recommended of the weekly voluntary fasts.

Three Days of Each Month (Ayyam al-Bid)

The Prophet (PBUH) recommended fasting three days of every lunar month, and he advised that this is like fasting the whole year — since each good deed is multiplied tenfold. He particularly encouraged fasting on the 13th, 14th, and 15th of each lunar month, which are called Ayyam al-Bid (the bright days), when the moon is full. Abu Dharr (RA) reported the Prophet (PBUH) saying: "O Abu Dharr, if you fast three days of a month, fast the 13th, 14th, and 15th" (Tirmidhi, Nasa'i). The Hanafi school does not restrict the three days to these specific dates but considers any three days valid.

Fasting Alternating Days: The Best Voluntary Fast

The Prophet (PBUH) said: "The most beloved fasting to Allah is the fasting of Dawud (David, AS) — he used to fast one day and not fast the next" (Bukhari and Muslim). Abdullah ibn Amr ibn al-As (RA) wished to fast every day, but the Prophet (PBUH) told him that was too much and guided him toward alternating fasting, calling it the best approach for those able to sustain it. This fast represents a lifelong balance between fasting and nourishing the body, a middle path the Prophet (PBUH) consistently praised.

Fasting the Months of Sha'ban and Rajab

Aisha (RA) narrated that the Prophet (PBUH) fasted more in Sha'ban than any other month (Bukhari and Muslim). When asked why, he explained that Sha'ban is a month between Rajab and Ramadan that people neglect, and it is a month when deeds are raised to Allah — and he loved that his deeds be raised while he was fasting. Regarding Rajab, there are no authentic specific hadiths designating fasting in Rajab as distinct from general voluntary fasting, and scholars caution against singling it out as a unique act, though fasting voluntarily in Rajab is not prohibited.

What Invalidates the Virtue of Voluntary Fasting

Unlike obligatory fasting, a voluntary fast may be broken without sin, though it should ideally be completed once begun. The Prophet (PBUH) permitted Aisha (RA) and Hafsa (RA) to break their voluntary fast when a gift of food arrived and they had already eaten (Muslim). If a person breaks a voluntary fast, they are not required to make it up, though the Hanafi school holds that making it up is wajib if it was begun with intention. The other three schools hold that the voluntary faster may break it without obligation to compensate.