CHAAST NAMAAZ (nafil)
Prophet Muhammad ﷺ said, 'whoever is punctual on the performance of Chaast Namaaz, his sins will be forgiven even if they are equal to the amount of foam in the ocean'.
Prophet Muhammad ﷺ said, 'whoever performs two rakaats of Chaast Namaaz, he will not be counted from among the neglectful ones (his sins will be forgiven), whoever performs four rakaats, he will be recorded amongst the worshippers, whoever performs six rakaats, it will suffice for him on behalf of any optional act for that day, whoever performs eight rakaats, Allah Ta'ala will count him to be among the obedient ones, whoever performs twelve rakaats, Allah Ta'ala will build him a house in Jannah'. (Al-Tabrani)
The best time to perform Chaast Namaaz is when a quarter of the day has passed i.e. the sun has risen high and there is heat in its rays.