Where it is written that fasting time starting and end in which Hadith book, how about the six months day or night continuously fasting time.
بسم الله الرحمن الرحيم
(Fatwa: 1161/1118/L=09/1436)
The starting and ending time of sawm is mentioned in the holy Quran:
حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ مِنَ الْفَجْرِ ثُمَّ أَتِمُّواْ الصِّيَامَ إِلَى الَّليْلِ [البقرة : 187]
(2) People living in such areas shall follow the timetable of the nearest cities of their country.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband