Question: Assalamu Alaikum Mufti Sahab, Hope you are well and InshaAllah hope to see you soon.
I have been researching about how we have differences in Salah due to them being taken out at different degrees, 

now i read the other question posted about Isha/taraveeh time posted by a Hafiz sahab and your answer to it clarifies many things, however the question i wanted to ask is about the Sehri times. What Degree do Ulamas use to give one hour extra time for Sehri ?? Not all Mosques do it but some of our Sunni Mosques do.

JazakAllah.
Answer:
Wa Alaykum Al-Salam,

The Imams of all schools are united on the time of Fajr which is the time to end the eating of Sehri. The time for Fajr begins when the sun is 18 degrees below the Horizon as has clearly been proven in Dar Al-Qubh An Waqt Al-Subh by the great Imam Ahmad Raza (Allah is pleased with him). The scholars of astronomy are also united on the fact that the twilight begins when the sun appears 18 degrees below the horizon of sunrise which is the break of dawn, end of sehri and beiginning of Fajr. Those people who continue eating after this time has occured, whether that be by mistake or due to following the wrong time table (whether it has been wrongly verified by a Mufti or an Aalim) have not fasted that day. They will have to do Qaza and no Kaffarah is upon them. This is clear in the book of fasting according to our Fuqaha.

As for the one hour extra given in some Masjids, this is nothing but ignorance. This is not based on any degree. This is based on the baseless rule of removing 1 hour and 20 minutes from the time of Fajr, splitting the night in to seven parts and labelling the final part as Fajr or on another basis which has no basis in the Hanafi Law. This is impermissible and worthy of Allah's punishment. Those people who eat for an hour extra after the break of dawn are accountable for missing their fasts as has been mentioned above. Blaming the Masjid committee will not free them from liability and blindly following them is a separate offence. There is no fatwa of a Mufti or Scholar to support such incorrect and invalid timings. These people should fear Allah and fear the questioning on the day of Judgement. May Allah guide the Muslims.

"Some people have thought the final seventh part of the night is Fajr, this is absolutely incorrect" (Bahar-e-Shariat) 

And Allah knows best.

Zahid Hussain Al-Qadri
(Beggar at the doorstep of Scholars)