Ruling on singling out Fridays for visiting graves

Praise be to Allaah. 

There is no basis for that. What is prescribed is to visit graves
at any time of night or day that suits the visitor. With regard to singling
out a particular day or night, this is bid’ah and there is no basis
for this, because the Prophet (peace
and blessings of Allaah be upon him) said: “Whoever innovates anything
in this matter of ours (Islam) that is not a part of it will have it
rejected.” (Saheeh, agreed upon). And he
(peace and blessings of Allaah be upon him) said: “Whoever does anything
that is not a part of this matter of ours (Islam) will have it rejected.”
(narrated by Muslim in his Saheeh from ‘Aa’ishah, may Allaah
be pleased with her).