Question Summary:
Intention for fasting

Question Detail:

If before going sleep i make intention that im going to keep my qadha fast (when i wake up for sehri) but then i don't end up waking up for sehri, now is it ok if i dont fast that day? Or had my fast started? If it had started but because i didnt knw  do i hav to make qadha of it? And is it the same ruling for nafal/sunnah fast? Jzkk

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
 
The intention for a Qadha fast must be made the night prior to fasting. Once the intention is made if you do not wish to fast you must renew your intention (of not fasting) before termination of Sehri. As soon as Sehri ends your fast has commenced. If you break the Qadha fast, you will be sinful and you must repeat the Qadha. Therefore, in your situation the fast had commenced and the Qadha is still upon you.[1]
In the case of Nafl fasts, although it is better to make the intention the previous night, it is permissible to make intention before  ضحوة الكبرى(exactly midway between Subh Sadiq and sunset is called Dahwatul Kubra). However, if you have made the intention of a Nafl fast the night before, and after Sehri ends you decided to nullify the fast, then it is necessary to make Qadha of the Nafl fast. Once the intention of keeping a Nafl fast has been made, then if you do not wish to keep the fast you should change your intention before Sehri ends.[2]
 
And Allah Ta’āla Knows Best
Saleem Khan
Student Darul Iftaa
Bradford, UK
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net