The White Days

[1] Muslims believe that the white days of the lunar months of Rajab, Sha'ban and Ramadan are very virtuous.

[2][3] This idiom has originated from the idea that the nights in these three days are bright and white due to the fullness of the moon.

[citation needed] Muslims believe the most virtuous practices to perform on the White Days are fasting and spiritual retreat.

[4] Fasting on the White Days is recommended according to many Islamic schools of jurisprudence.

Tala’al-badru ‘alayna Min thaniyyatil-wada’ Wajaba al-shukru ‘alayna Ma da’a lillahi da’ O the white moon rose over us from the valley of Wada And we owe it to show gratefulness Where the call is to God

The White Days of certain months such as Rajab, Sha'ban, and Ramadan, are considered more important, and are days of celebration. Jamkaran Mosque, Qom.
The White Days of certain months such as Rajab, Sha'ban, and Ramadan, are considered more important, and are days of celebration (according to the shi'a sect).