Time for Imsaak (Starting the Fast) when the Calendar Times are Different
Question

                There are apparent discrepancies in the times of Salaat-ul Fajr stated on the different 
timetables distributed by the various mosques of the same town or city. Would it be 
a ‘safer’ practice if one was to follow the earliest of those times for the purpose of 
Imsaak (abstaining from eating, drinking, etc.)?
Praise be to Allah.It is permissible to eat, drink, etc. until one is certain of the time of Fajr (interpretation of the 
meaning): “…eat and drink until the time where the ‘white’ and ‘black’ thresholds of Al-Fajr is 
evident to you…” [Soorat-ul Baqarah] 
So, this means it is permissible to continue eating and drinking unless it is evident for one that it is 
time for Fajr. Fajr can be defined as the ‘white’ light spreading across the horizon from the 
eastern side. If one was unable to sight Al-Fajr and there was no one else who could tell him 
about it through means such as raising the Azaan (The call to prayers), then one should follow the 
timetable that, according to the best of his knowledge, is the most accurate. This accuracy is 
usually established through experience or by asking experts or the earlier Muslim residents of the 
area.