Voluntary Fasting in Islam
Suggest editOverview and Virtue
Voluntary fasting (sawm al-tatawwu' or sawm al-nafl) is among the most beloved acts of worship to Allah. Unlike the obligatory fast of Ramadan, voluntary fasts can be observed on specific recommended days throughout the year, offering a Muslim the opportunity to draw closer to Allah continuously. The Prophet Muhammad himself fasted regularly outside Ramadan, and the Quran highlights fasting as a uniquely personal act of worship: the Prophet transmitted from Allah the hadith qudsi: 'Every deed of the son of Adam is for himself except fasting — it is for Me and I shall reward it' (Sahih al-Bukhari 5927).
Voluntary fasting serves multiple spiritual and practical purposes: it disciplines the nafs (self), guards against desires, increases gratitude for the blessings of food and drink, and creates a heightened state of consciousness and God-awareness (taqwa) throughout the day.
Recommended Fasting Days
Mondays and Thursdays were the days the Prophet most consistently fasted outside Ramadan. He explained: 'Deeds are presented to Allah on Mondays and Thursdays, and I love that my deeds be shown while I am fasting' (Sunan al-Tirmidhi 747, graded hasan). Aisha reported that the Prophet was more eager to fast on these two days than any others (Sahih Muslim 1156).
The Three White Days (Ayyam al-Bid) — the 13th, 14th, and 15th of each lunar month — are so called because of the bright full moon. The Prophet said: 'Fasting three days of every month is equivalent to fasting the entire year' (Sahih Muslim 1162), and when asked which three days, he indicated these lunar mid-month days. Abu Dharr al-Ghifari reported that the Prophet commanded him to fast these days every month (Sunan al-Nasa'i 2406).
The Day of Arafah (9th Dhul Hijjah) is the single most virtuous voluntary fast of the year for those not performing Hajj. The Prophet said: 'I seek from Allah that fasting on the day of Arafah may atone for the sins of the year before it and the year after it' (Sahih Muslim 1162). Pilgrims at Arafah do not fast on this day, as the Prophet broke his fast there in view of the people to show that the pilgrim does not fast.
Ashura — the 10th of Muharram is another highly recommended fast. The Prophet found the Jews of Madinah fasting this day, learned it commemorated the day Allah saved Musa from Pharaoh, and said: 'We have more right to Musa than you,' and fasted and commanded fasting on it. Its reward is expiation of the sins of the previous year (Sahih Muslim 1162). The Prophet intended to add the 9th of Muharram to distinguish Muslim practice from Jewish practice (Sahih Muslim 1134).
Six Days of Shawwal: The Prophet said: 'Whoever fasts Ramadan and then follows it with six days of Shawwal, it is as though he fasted the entire year' (Sahih Muslim 1164). Scholars explain this mathematically: Ramadan equals ten months of fasting in reward (each day multiplied by ten), and the six days of Shawwal equal two months, totaling twelve — a full year. These days can be fasted consecutively or spread throughout the month.
Sha'ban: Aisha reported that the Prophet fasted more in Sha'ban than in any other month outside Ramadan (Sahih al-Bukhari 1969). Scholars understand this as fasting most of the month, not necessarily all of it. The Prophet explained this was a month whose deeds are raised to Allah, and he liked his deeds to be raised while fasting.
Prohibited and Discouraged Fasting
Islam also specifies days on which fasting is prohibited or discouraged. Eid al-Fitr and Eid al-Adha: Fasting is strictly prohibited on both Eid days. The Prophet said: 'No fasting on these two days — they are days of eating and drinking and the remembrance of Allah' (Sunan al-Nasa'i 3003). Ayyam al-Tashreeq (11th–13th Dhul Hijjah): Fasting is prohibited on these three days following Eid al-Adha, as they are days of celebration and eating the sacrificial meat, with an exception for the Hajj pilgrim who cannot afford a sacrifice (Sahih Muslim 1141).
Fasting every single day (sawm al-dahr) without break is discouraged. When the Prophet was told that a man fasted every day, he said: 'He neither fasted nor broke his fast' — indicating that the spiritual benefit diminishes when fasting loses its contrast with eating (Sahih al-Bukhari 1977). The optimal fasting, the Prophet said, is the fast of Dawud: fasting alternate days (Sahih al-Bukhari 1976). Singling out Friday or Saturday alone for fasting is also discouraged, though fasting either day as part of a larger pattern (e.g., Monday–Thursday includes Friday, or fasting alternate days) is permissible.
Intention and Ruling
The intention for voluntary fasting can be made during the day itself, even after sunrise, as long as no food has been eaten since Fajr — a ruling established by the report that the Prophet would ask Aisha in the morning: 'Do you have any food?' and when she said no, he would say: 'Then I am fasting' (Sahih Muslim 1154). A voluntary fast can also be broken if a legitimate need arises, such as an unexpected guest, though the faster should ideally make it up later.