These include the white days (The thirteenth, fourteenth, and fifteenth days of each lunar month.

They are called white days because their nights are lit by the full moon. )

Abu Tharr (G. p. H) said: "The Messenger of Allah (P. B. U. H) said:

"0 Abu Tharr, if you fast three days of a month then make them the thirteenth, fourteenth, and fifteenth. '"

[Al-Tirmithi, Vol. 3, The Book of Fasting, Chapter 54/761].

Also, it is recommended to fast the black days'.

(The twenty eighth, ninety eighth, and thirtieth days of each lunar month, so called because they have no moon).