Ruling 1661 — Fasting (Ṣawm)

If in the month of Ramadan, after investigating (by looking at the horizon to sight the true dawn),[2] it is not known to someone that the time of ṣubḥ prayers has set in, and he does something that invalidates a fast, and afterwards it becomes known that it was ṣubḥ, then qaḍāʾ is not necessary.