In the Name of Allah, Most Gracious, Most Merciful.

 

All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.

 

Thank you for your good question.

 

Dhul-Hijjah days are favored by Almighty Allah over other days. It was also narrated from Anas (may Allah be pleased with him) that the Prophet (peace be on him) said: “There is no deed that is better before Allah or more greatly rewarded than a good deed done in the (first) ten days of Ad-Adha.)…” (Ad-Darimi)

 

Ibn `Abbas (may Allah be pleased with him) reported that the Prophet (peace be on him) said: “There are no days on which righteous deeds are more beloved to Allah than these ten days (of Dhul-Hijjah)….” (Al-Bukhari)

 

The Prophet (peace be on him) used to fast on the first nine days of Dhul-Hijjah. It was narrated from Hunaydah ibn Khalid from his wife, that one of the wives of the Prophet (peace be on him) said: The Prophet (peace be on him) used to fast on the first nine days of Dhul-Hijjah…” (An-Nasaa’i)

 

If someone fasts on Dhul-Hijjah days with the intention to make up for missed fast-days of Ramadan, he or she will be rewarded for making up for what he or she has missed from Ramadan fast-days and for the Sunnah fasting of Dhul-Hijjah. This opinion is supported by many scholars including the Shafi`i jurists.

 

So, you may make your intention to make up for what you have missed from Ramadan fast-days when you fast on Dhul-Hijjah days to get the two rewards: making up for what you have missed from Ramadan and the Sunnah fasting of Dhul-Hijjah.

 

May Allah accept your and our good deeds, ameen.

 

Allah Almighty knows best.