On the last day of Rajab pray the prayer of Salman-e-Farsi.
It is like this:
10 Rakaats prayer Pray in 5 sets of 2 units each. In every unit recite Sura Faatihah once, Sura Ikhlaas 3 times & Sura Kafiroon 3 times.
There is no god save Allah, no one other than him; sovereignty belongs to HIM. All praise is for HIM alone, gives life, puts to death, (because) HE is ever living, Immortal; in His hand is the good He is able to do all things
After this recite:
Blessings of Allah be on Muh'ammad and on his purified children. There is no power, nor strength, save with Allah