About the White Days

Fasting Ayyām al-Bīḍ (13th–15th each Hijri month)

Ayyām al-Bīḍ ("the White Days") are the 13th, 14th, and 15th of each Hijri lunar month — named for the brightness of the full moon on these nights. Fasting these three days each month is a Sunnah that the Prophet ﷺ commanded and practiced throughout his life.

They are the most recommended three-day fast of any given month, providing a regular rhythm of worship year-round.

Significance & benefits

Reward Equal to a Lifetime of Fasting

The Prophet ﷺ said: "Fasting three days of every month is like fasting for a lifetime" (Bukhari 1979, Muslim 1160). This is because each good deed is multiplied tenfold — 3 days × 10 = 30 days, equivalent to a full month; done every month, it equals a full year.

The Explicit Command

Abū Dharr رضي الله عنه reported: "The Messenger of Allah ﷺ commanded us to fast three days of every month: the 13th, 14th, and 15th" (Nasā'ī 2424, Tirmidhi 761).

The Prophet's Own Practice

Ibn Millān reported that the Prophet ﷺ never abandoned fasting the White Days whether he was at home or travelling (Nasā'ī 2345). This lifelong consistency is a mark of how important these three days are.

Why These Days?

They coincide with the full moon — the brightest nights of the lunar month — making them a natural marker for the monthly fast cycle. The brightness of the moon on these nights is also said to symbolise spiritual illumination.

Benefits

  1. Consistent year-round worship — not only in Ramadan.
  2. Reward of a lifetime's fasting through multiplication of deeds.
  3. Self-discipline on a regular, manageable schedule — three days per month.
  4. Following a direct command and consistent practice of the Prophet ﷺ.
  5. Spiritual connection to the natural cycle of the lunar calendar.

How to perform / practice

Mark Your Calendar

The 13th, 14th, and 15th of each Hijri month can be tracked using any Islamic calendar or prayer time app. Note that Hijri months follow the lunar cycle and the dates shift relative to the Gregorian calendar each year.

Intention

Make your intention (niyyah) the night before each day of fast.

During the Fast

Fast from Fajr to Maghrib on each of the three days — abstaining from food, drink, and intimacy.

Break the Fast

At Maghrib, break with dates and water. Do not delay Maghrib for iftar.

Exceptions and Priorities

  • If the 13th falls on Eid al-Adha (15th of Dhul Hijjah, following the 10th), skip that day — fasting on Eid is forbidden. Move the fast to another day in that month or substitute.
  • Complete any obligatory Ramadan make-up fasts before adding voluntary fasts.
  • Even fasting one or two of the three days carries reward, though all three is best.
  • There is no makeup required if you miss them without excuse — they are voluntary.

References