The ruling on one for whom the sighting of the crescent moon is confirmed during the day

The questioner : We remain on the issue of what happens if the sighting of the crescent moon is confirmed during the day. What is the ruling? Is it obligatory for them to abstain from food and drink and make up the fast, or is it obligatory for them to abstain without making it up, or is there no obligation to abstain and they must make up the fast?

The Shaykh : Some scholars hold that it is obligatory for them to abstain and make up the fast, and this is the well-known position in the school of Imam Ahmad. It is obligatory for them to abstain because it has been established that this day is from Ramadan, and it is obligatory for them to make it up because they ate at the beginning of the day. Thus, it is obligatory for them to abstain and make it up. Shaykh al-Islam Ibn Taymiyyah chose the position that it is obligatory for them to abstain without making it up. It is obligatory for them to abstain, why? To fulfill the fast, because it has been established that the day is from Ramadan, so it is obligatory for them to fast. It is not obligatory for them to make it up because they were eating and drinking at the beginning of the day. What time were they in?
Two witnesses who are not just, so it is as if a person ate thinking that the dawn had not appeared, and then it turned out that it had. But this second issue is a daily error, while the first is a monthly error. Those people erred in the month; they did not know that [it was Ramadan], and these second people erred in the day; they did not know that the dawn had appeared. However, the ruling for both issues is the same according to the first opinion, which is the school’s position: if a person ate thinking that the dawn had not appeared and then it turned out to be [dawn], it is obligatory for him to abstain and make it up. But what Shaykh al-Islam chose is more correct, because Allah the Exalted says:
In this issue, did they intend? We say, yes, they did not intend, because they did not know. Otherwise, the natural instinct of every Muslim is that if tomorrow is from Ramadan, he is fasting. The intention follows knowledge. So if they intended to fast that day, but they did not know that it was from Ramadan, what is the ruling?
It is not permissible. We do not accept advancing Ramadan by fasting one or two days. In this issue, we now say: if the sighting of the crescent moon is confirmed during the day, what is the ruling? We said there is a disagreement between these two positions. Some hold that it is obligatory for them to abstain and make it up. It is obligatory for them to abstain because it has been established that the day is Ramadan, but not to make it up, why? And to make it up because they were eating during the day. The second position is that it is obligatory for them to abstain without making it up, because they were ignorant. And Allah willing, in the conditions of the concise texts, we will come to what indicates the preference for this opinion.