Prayer timetables vary a lot; therefore, how do we determine the time of dawn (Fajr) in order to abstain from eating and drinking and perform prayer?
The time of fajr starts when light spreads horizontally from the eastern horizon and continues to increase in brightness. Thus, a person must have knowledge or attain contentment that it has occurred. Prayer timetables are based on estimated astronomical calculations. Thus, a person may rely on them if they are content in their accuracy. Otherwise they should observe precaution by abstaining from eating and drinking a few minutes before the estimated time of fajr and delaying the morning prayer by a few minutes.