The White Days: three moonlit days of fasting every month

Step outside on the 13th, 14th or 15th night of any Hijri month and you will see where the name comes from: the moon is full, and the nights are washed white with its light. These are the Ayyam al-Beed — the White Days — and fasting them is one of the most beloved monthly habits the Prophet ﷺ taught his companions.

What the Prophet ﷺ said about them

Two narrations carry the heart of it. The first gives the promise:

“Fasting three days of every month is like fasting for a lifetime.”

And the second names the days:

“O Abu Dharr, if you fast three days of the month, then fast the thirteenth, fourteenth and fifteenth.”

Why "like a lifetime"?

Scholars explain it through the principle in the Quran (6:160) that a good deed is rewarded tenfold. Three days multiplied by ten is thirty — a whole month. Keep that up every month and, in reward, you have fasted the whole year. Keep it up every year, and the arithmetic of mercy quietly turns three days a month into a lifetime of fasting.

That generosity is the point. Most of us cannot fast constantly, and the sunnah never asks us to. Three days, once a month, on nights bright enough to remind you — that is a habit a working parent, a student in exam season, or a traveller can actually keep.

Practical notes

• The days are counted on the Hijri calendar, so they drift about eleven days earlier each Gregorian year. A calendar feed or a reminder email saves you the mental arithmetic.
• Even one of the three days is beloved — the three are the fullest form, not an all-or-nothing rule.
• Your intention is simply the decision, made before Fajr, that you are fasting tomorrow. No special words are needed.
• A small suhoor — even water and a few dates — makes the day far easier.
• One month a year is special: in Dhul Hijjah the 13th falls in the days of Tashreeq, when fasting is not allowed, so only the 14th and 15th are fasted that month.

When are the next White Days?

They begin on the 13th of every Hijri month. You can see the exact upcoming Gregorian dates for your location on our upcoming fasting days page, add them permanently to Google or Apple Calendar with the free calendar feed, or simply let sunnahfast email you the evening before — around 7 PM your local time, with the dates written out.