Abu Qatada (Radiyallahu 'anh) relates that the Holy Prophet (Sallallahu ‘alayhi wa Sallam) said that the fast on the 10th of Muharram atones for the sins of the preceding year. [Sahih Muslim]
so does that mean i keep this roza, and then i can do alot of bad things a year after knowing i will be forgiven by default?!
Remember one rule, if hadees is stating BIGGGGGGGGGGGGGGGGGGGG reward in return of small good deed, then the hadees is fabricated...
The most beneficial of all fasts are the fasts of Ramadan... Fast of Zil-Haj, Shaban and MUharam and fasting on Monday and Thursday are Nafli and have relatively less blessings...