Preferred time to stop eating is ten minutes before Fajr time. So if the Fajr time is 6:12 a.m., one should stop eating around 6 a.m. Permitted time for eating suhur, however, extends up to 6:12 a.m., after which time it is considered unlawful.
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When should you stop eating at Suhoor?
Most scholars agree that suhoor can be eaten until the beginning of the ‘first light’ of dawn which is up until the point that sunlight first becomes visible. Suhoor is eaten before Fajr time. You can find out what time Suhoor ends for each day during Ramadan 2023 here.8 במרץ 2023