Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 1 month ago

If you were sure that the real Fajr has happened then you ate even after one second after Fajr, your fast will be invalid. If you ate because you were not sure whether Fajr has happened or not and you ate thinking it did not happene yet, then your fast is valid.