How to Fast the Sunnah Days

Which days are the sunnah fasts?

The sunnah fasts are voluntary, not obligatory like Ramadan, and the tradition records a recognizable set of them. The weekly ones are Mondays and Thursdays. The monthly ones are the white days — the 13th, 14th, and 15th of each Hijri month, named for the nights when the moon is full and the sky is bright. The annual ones cluster around two seasons. Ashura falls on the 10th of Muharram and is commonly observed together with the 9th. The first days of Dhul Hijjah lead up to the Day of Arafah on the 9th, which is fasted by those who are not performing Hajj. And six days in Shawwal are fasted after Eid al-Fitr.

None of these are obligations, and nobody is expected to keep all of them. The tradition treats them as opportunities rather than duties — you can fast one Monday, skip the next, and have done nothing wrong. It also means the rules around them are lighter than Ramadan's in ways that vary by school, so take the details from your own teachers rather than from a table.

How do you track Hijri dates against a Gregorian calendar?

You track them by working from a Hijri calendar and setting reminders a day early, because the two calendars do not line up. A lunar month runs 29 or 30 days, so the Hijri year is about eleven days shorter than the Gregorian one and every lunar date drifts earlier each year. The white days land on different Gregorian dates every single month, which is why people who intend to fast them and rely on memory alone usually miss them. Mondays and Thursdays are the exception — they sit on the Gregorian week.

One caveat matters more than any other here: Hijri dates shown in apps and printed calendars are calculated, and they are approximate. The actual start of a lunar month depends on the sighting of the new crescent moon, which can differ by a day between regions and authorities. Treat any advance date as an estimate, confirm Ashura, Arafah, and the start of Shawwal with your local mosque or moon-sighting authority, and expect the occasional one-day shift. This is normal, not an error.

• Islamic calendar
• Day of Ashura
• Day of Arafah

How do you begin a voluntary fast?

You begin with the intention (niyyah) and, if you can, a pre-dawn meal. The intention is an inward resolve to fast for the sake of God rather than a formula to recite, and it is what separates a fast from simply not having eaten. For voluntary fasts the schools differ on when that intention must be formed — some hold that it may be made after dawn provided nothing has been eaten or drunk, which is a genuine concession that does not apply in Ramadan. Because that detail differs, take it from your own school rather than assuming one position is universal.

The rest of the day follows the shape of a Ramadan fast. Suhoor before Fajr is encouraged even when it is light, the fast runs from the start of dawn to sunset, and it is broken promptly at Maghrib. Because a voluntary fast is not a make-up or an obligation, the day is a good place to add something beyond abstaining — a portion of reading, some extra du'a.

Are there days when fasting is not observed?

Yes. The tradition teaches that the two Eids are not days of fasting. Eid al-Fitr on the 1st of Shawwal and Eid al-Adha on the 10th of Dhul Hijjah are days of eating and celebration, and fasting is not observed on either. The days immediately after Eid al-Adha are also widely treated as days of eating, with the details varying between schools and circumstances. This is worth knowing before you plan anything around Dhul Hijjah or Shawwal.

Two practical consequences follow. The six days of Shawwal begin after Eid al-Fitr, never on it. And the encouraged fasting in Dhul Hijjah runs through the 9th, the Day of Arafah, and stops there — the 10th is Eid. If a white day or a Monday happens to land on an Eid, the Eid takes precedence. For anything more specific than this, and for how your school handles the days after Eid al-Adha, ask a qualified scholar rather than working it out from a calendar.

• Eid al-Fitr
• Eid al-Adha

Do all schools and traditions observe these days the same way?

No, and this is the most important thing to carry away from any general guide, including this one. The broad encouragement toward voluntary fasting is widely shared, but which days are emphasized, how strongly, and what the details are differ between the schools of fiqh — Hanafi, Maliki, Shafi'i, Hanbali, and Ja'fari — and between traditions more broadly. The weight given to the six days of Shawwal, for instance, is not identical across the schools. None of that is a defect; it reflects long-standing differences in how the same sources are read.

Ashura is the clearest case. Its significance and its observance differ across traditions — Sunni and Shia practice around the day is not the same, and the day carries a different meaning in each. We deliberately do not adjudicate that here and we do not summarize its history, because neither an article nor an app is the right place for it. Take Ashura, and the rest of these days, from a qualified scholar and teachers within your own tradition. That is not a hedge; it is how this material has always been transmitted.

Should you fast the sunnah days if you are unwell?

That is a decision for a doctor and a qualified scholar, not for a guide. Well-established exemptions from fasting exist — illness, pregnancy, nursing, travel, menstruation and post-natal bleeding, frailty, and chronic conditions such as diabetes — and they apply to voluntary fasts as much as to Ramadan. If anything, the case is stronger here. A voluntary fast is precisely the one you are free not to keep, so there is no reason to undertake it against medical advice.

We give no medical guidance and no fiqh ruling on this, and you should be wary of any article or app that does. If you take medication on a schedule, manage blood sugar, are pregnant or nursing, or live with a condition that food and fluid timing affects, speak to your doctor about the health side and a qualified scholar about the fiqh before adding voluntary fasts. Dizziness, a pounding headache, or confusion during a fast are reasons to stop and seek advice — protecting your health is part of the tradition, not a failure of it.

How do you build a sunnah fasting habit that lasts?

Start with one day, not a calendar. The most common way people fail at sunnah fasting is by deciding to keep Mondays, Thursdays, the white days, and everything in Dhul Hijjah all at once, which lasts about three weeks. One Monday a week, kept for a couple of months, is a habit; six days a month attempted in January is a resolution. Add the second day only once the first feels ordinary.

Anchor the practice to things already in your week. Suhoor sits next to Fajr, so a fast day is easier when your prayer times are somewhere you already look, and iftar at Maghrib gives the day a fixed end. Prepare the night before rather than at 4am — the decision, not the hunger, is what usually breaks the habit. Then track it — with a lunar calendar you genuinely will not remember when the white days are.

• Prayer times by city
• Verses about fasting

How can Living Quran help you keep track?

Living Quran is our app, and the part of this it can genuinely help with is the bookkeeping. Its fasting tracker sits on a Hijri calendar, so the white days, Ashura, Arafah, and the six of Shawwal are visible against the Gregorian dates you actually live by, and you can mark them as you keep them. Prayer times are computed on your device, which gives you local Fajr and Maghrib for suhoor and iftar without your location leaving your phone. Hijri dates in the app are calculated, so confirm the moon-dependent ones locally.

What it will not do is tell you whether to fast. Noor, the app's study companion, is a study aid and not a mufti — it cites its sources, stays neutral across the five schools, notes where they differ instead of quietly picking one, and defers rulings to a qualified scholar. It never issues fatwas. That is the honest boundary, and it is the same one this guide keeps — an app can remind you what day it is, and a scholar tells you what to do about it.

• How to fast in Ramadan
• How to pray on time
• Read the Quran
• Du'as for every occasion