Voluntary Fasting Outside Ramadan: Mondays, Thursdays, White Days and More

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Ramadan ends, and with it we sometimes seem to lose the spiritual discipline built over an entire month. What if that discipline could continue, in another form, throughout the year? Prophet Muhammad ﷺ never limited fasting to the sacred month alone — he regularly fasted outside Ramadan himself and taught his community several specific voluntary fasts, each with its own virtue, wisdom and place in the lunar calendar. This guide brings together these voluntary fasts — Mondays and Thursdays, the three white days of each month, the Day of Ashura, the six days of Shawwal and the month of Sha’ban — with their authentic evidence, so that you can choose how to keep this act of worship alive throughout the year according to your daily routine. To learn all about the obligatory fast of Ramadan, see our complete guide to Ramadan. And for fasting on the Day of Arafah, one of the most rewarding days of the year, find all the details in our article on the first ten days of Dhul-Hijjah.

1. Why fast outside Ramadan?

Voluntary fasting (siyam an-nafl) holds a unique place among acts of worship. Unlike prayer or charity, whose value is immediately visible to others, fasting is a secret between the servant and Allah — no one can verify whether you have secretly eaten or drunk. This is precisely why Allah says in a hadith qudsi:

“Every deed of the son of Adam is for him, except fasting: it is for Me, and I am the One who rewards it. He gives up his desires and his food for Me.”

— Narrated by Al-Bukhari (no. 1904) and Muslim (no. 1151), from Abu Hurayrah رضي الله عنه

What this hadith means in practice: Because fasting is hidden from people’s eyes, its reward is not subject to the usual measure — Allah Himself takes charge of it directly, with no specified limit. This is one reason why the Prophet ﷺ provided many opportunities to fast voluntarily throughout the year, offering his community numerous ways to return to this act of worship outside Ramadan alone.

2. Monday and Thursday fasting

This is the most regular and best-documented voluntary fast in the Sunnah. ‘A’ishah رضي الله عنها reported that the Prophet ﷺ was particularly keen to fast on these two days of the week:

“The Messenger of Allah ﷺ would choose to fast every Monday and Thursday.”

— Narrated by At-Tirmidhi, Ibn Majah, Abu Dawud and An-Nasa’i, from ‘A’ishah رضي الله عنها

The Prophet ﷺ himself explained the reason for this choice:

“Deeds are presented [to Allah] on Mondays and Thursdays, and I like my deeds to be presented while I am fasting.”

— Narrated by At-Tirmidhi (no. 747), authenticated by Al-Albani in Sahih At-Tirmidhi, from Abu Hurayrah رضي الله عنه

A version narrated by Ibn Majah adds a second virtue, just as immense:

“The gates of Paradise are opened on Mondays and Thursdays, and Allah forgives every servant who associates nothing with Him — except someone who is in conflict with his brother. It is then said: ‘Give these two time until they reconcile.’”

— Narrated by Muslim, from Abu Hurayrah رضي الله عنه

What this hadith means in practice: This immense virtue — forgiveness linked to the opening of the gates of Paradise — has one exception: unresolved conflicts between Muslims. It is a powerful reminder that reconciliation with other believers is not merely a matter of social courtesy, but a condition that can directly affect the divine forgiveness granted to you on that day.

Monday also carries an additional, personal significance for the Prophet ﷺ, as he explained when asked about fasting on this day:

“It is the day on which I was born, and the day on which I received revelation.”

— Narrated by Muslim (no. 1162), from Abu Qatadah Al-Ansari رضي الله عنه

Sheikh Ibn ‘Uthaymin رحمه الله noted, on the basis of this additional explanation, that fasting on Monday is even more emphasised (mu’akkad) than fasting on Thursday, although both are authentically established and strongly recommended.

3. The three white days of each month (Ayyam Al-Bid)

The Ayyam Al-Bid (أيام البيض) — literally ‘the white days’ — are the 13th, 14th and 15th days of each lunar month, so called because their nights are illuminated by the full moon. The Prophet ﷺ strongly recommended fasting on these three days each month. Abu Dharr Al-Ghifari رضي الله عنه reported:

“O Abu Dharr, if you fast three days of each month, fast on the 13th, 14th and 15th.”

— Narrated by At-Tirmidhi (no. 761), authenticated by Al-Albani

Abu Ad-Darda’ رضي الله عنه reported that the Prophet ﷺ had particularly recommended this practice to him as one of three things he should never abandon:

“My beloved [the Prophet ﷺ] recommended three things to me that I will never abandon until I die: fasting three days each month, praying Witr before sleeping, and performing two units of Duha prayer.”

— Narrated by Muslim (no. 722), from Abu Ad-Darda’ رضي الله عنه — A similar version, transmitted by Abu Hurayrah رضي الله عنه, is also narrated by Al-Bukhari (no. 1981)

The virtue of this monthly fast is considerable: a fast rewarded tenfold, multiplied by three days, amounts to the equivalent of a full month — and therefore, over the entire year, to the equivalent of continuous fasting:

“Fasting three days of each month is equivalent to fasting continuously throughout the year.”

— Narrated by Al-Bukhari and Muslim, from Abu Hurayrah رضي الله عنه

A useful clarification: According to hadiths narrated by Abu Dawud and An-Nasa’i, the Prophet ﷺ did not always make a point of fasting precisely on the 13th, 14th and 15th days — some reports mention that he sometimes fasted on the first Monday of the month followed by two Thursdays, or the reverse. The most widespread scholarly position nevertheless remains to prioritise the three full-moon days (13, 14 and 15), as recommended in Abu Dharr’s hadith, while recognising some flexibility if it helps maintain regular practice.

4. Fasting on Ashura (10 Muharram)

The Day of Ashura falls on the 10th day of Muharram, the first month of the Islamic calendar. Ibn ‘Abbas رضي الله عنهما reported that the Prophet ﷺ personally fasted on this day and instructed others to do so:

“The Messenger of Allah ﷺ fasted on the Day of Ashura and instructed others to fast on it.”

— Narrated by Al-Bukhari and Muslim, from Ibn ‘Abbas رضي الله عنهما

The virtue of this fast is immense — although slightly less than that of fasting on Arafah:

“Fasting on the Day of Ashura — I hope that Allah will make it expiate the sins of the previous year.”

— Narrated by Muslim (no. 1162), from Abu Qatadah Al-Ansari رضي الله عنه

Why does Ashura expiate one year of sins, while Arafah expiates two? Ibn Al-Qayyim explains in Badai’ Al-Fawaid two reasons: first, the Day of Arafah falls in a sacred month (Dhul-Hijjah), preceded and followed by other sacred months — unlike Ashura. Second, fasting on Arafah is specific to the religious law of this community, whereas Ashura was already known and observed by earlier nations, notably to commemorate Prophet Musa’s عليه السلام deliverance from Pharaoh.

An important clarification: It is strongly recommended to fast on the 9th day of Muharram (called Tasu’a) as well as the 10th, to distinguish this practice from that of other religious communities who fasted only on the 10th day. The Prophet ﷺ had expressed his intention to do so the following year before his death.

5. The six days of Shawwal

Shawwal is the month immediately after Ramadan. Fasting six days during this month — after completing Ramadan in full — carries an extraordinary virtue, comparable to fasting an entire year:

“Whoever fasts Ramadan and then follows it with six days of Shawwal, it is as though they have fasted the entire year.”

— Narrated by Muslim (no. 1164), from Abu Ayyub Al-Ansari رضي الله عنه

What this hadith means in practice: The calculation rests on a Quranic principle — each good deed is rewarded at least tenfold (Surah Al-An’am, 6:160). The month of Ramadan (around 30 days) therefore amounts to 300 days of fasting, and the six days of Shawwal amount to 60 days. Together: 360 days, the equivalent of a full lunar year. These six days may be fasted consecutively or separately, at any time during Shawwal, according to personal preference.

A useful clarification for women: If you have Ramadan days to make up (for example, because of menstruation or illness), most scholars recommend making up these obligatory days first before fasting the six voluntary days of Shawwal, although some scholars allow the reverse when time is limited.

6. Fasting more during Sha’ban

Sha’ban is the month immediately before Ramadan. ‘A’ishah رضي الله عنها, the Prophet’s ﷺ wife, reported a striking observation about his practice during this month:

“He fasted all of Sha’ban — he fasted [almost] all of Sha’ban, except for a few days.”

— Narrated by Muslim (no. 1156), from ‘A’ishah رضي الله عنها

Usamah ibn Zayd رضي الله عنهما, surprised by this unusual frequency of fasting, asked the Prophet ﷺ directly about it:

“O Messenger of Allah, I have never seen you fast as much as you do during Sha’ban.” He replied: ‘It is a month between Rajab and Ramadan that people neglect. It is a month in which deeds are raised to the Lord of the worlds, and I like my deeds to be raised while I am fasting.’

— Narrated by An-Nasa’i, authenticated by Al-Albani, from Usamah ibn Zayd رضي الله عنهما

What this hadith means in practice: Sha’ban is a ‘forgotten’ month between two prominent points in the calendar — Rajab, one of the four sacred months, and Ramadan, the most important month. The Prophet ﷺ used precisely this period of reduced collective attention to increase his personal worship. It is also an excellent time for physical and spiritual preparation before Ramadan arrives.

A limit to be aware of: It is discouraged to begin a voluntary fast in the last one or two days of Sha’ban if you do not usually fast regularly, so as to clearly distinguish voluntary fasting from the beginning of Ramadan, which must be established with certainty through moon sighting.

7. Fasting on Arafah, in brief

Fasting on the 9th day of Dhul-Hijjah — the Day of Arafah — is the most rewarding of all voluntary fasts of the year, because it expiates the sins of two full years:

“Fasting on the Day of Arafah — I hope that Allah will make it expiate the sins of the previous year and the following year.”

— Narrated by Muslim (no. 1162), from Abu Qatadah Al-Ansari رضي الله عنه

This fast is for those who are not performing Hajj that year — for pilgrims standing at Arafah, most scholars discourage fasting that day, so that they can conserve the energy needed for supplications and the pilgrimage rites. For all the details about this fast and the first ten days of Dhul-Hijjah, see our complete article on this blessed period.

8. Days when fasting is prohibited

It is essential to know the days when voluntary fasting is strictly prohibited, so that you can organise your practice correctly.

9. How to make these fasts part of your daily life

With so many recommended fasts, it is natural to wonder which to prioritise if you cannot observe them all. Here are a few practical pointers:

10. Summary table of all voluntary fasts

❓ Frequently asked questions

Sources and references