Is it considered Sunnah or bid‘ah to designate specific dhikr and supererogatory prayers for each day, differing in the number of rak‘ahs, surahs, and their repetitions?

Designating each day with a specific dhikr (remembrance) or certain types of supererogatory prayers (nawafil) is an innovation (bid'ah), as this is not established in the Sunnah. A report by Sheikh Abdur-Razzaq Afifi concerning the book Al-Du'a Al-Mustajab (The Answered Supplication) stated that the book contained weak and fabricated hadiths, and it assigned a special litany to each day of the week, beginning and ending with specific verses and remembrances. This is among the newly invented innovations. It is recommended not to purchase this book or assist in its publication, in order to protect people from innovations and from worshipping Allah through weak and fabricated hadiths.