If a person intends to do the mustahabb action, that will not be acceptable for the obligatory action. If a person fasts with the intention of 'Ashura, that will not be acceptable as making up for a missed Ramadan fast, but if he intends to make up the missed Ramadan fast and does that on the day of 'Ashura, then his making up the missed fast will be valid, and there is the hope that he will also attain the reward for 'Ashura, according to some scholars.

1. According to the view of the majority of scholars, it is encouraged (mustahabb) to fast the first nine days of Dhul-Hijjah. 2. There are several scholarly opinions concerning the hadeeth of ‘Aishah according to which the Prophet (blessings and peace of Allah be upon him) did not fast these ten days. Please see the detailed answer for these views.

Fasting in Sha’ban in the second half is not allowed and that is either makruh or haram, except for the one who has the habit of fasting regularly or who is continuing after fasting during the first half of Sha’ban. For more, see the detailed answer.

It is recommended to fast a great deal in the month of Sha’ban. The Prophet Muhammad (peace and blessings be upon him) used to fast the whole of Sha’ban. For more, please see the detailed answer.

It is permissible to fast the day of 'Ashura on its own, but it is better to fast the day before it or the day after it.

It is recommended to fast both the ninth and the tenth of 'Ashura because the Prophet (peace be upon him) fasted the tenth and intended to fast the ninth.

Fasting the day of ‘Ashoora’ does expiate for the past year. The expiation of sins that is achieved by fasting ‘Ashoora’ refers to minor sins; with regard to major sins, they need separate repentance.