Sayyidah Asma' (may Allah be pleased with her) says: We broke our fast in the time of the Messenger of Allah (peace and blessings be upon him) on a cloudy day, then the sun appeared. (The narrator says:) I said to Hisham: "Were they then ordered to make it up?" He said: "That was unavoidable."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8011
Zayd bin Aslam narrates from his brother Khalid bin Aslam that Umar bin al-Khattab (may Allah be pleased with him) broke his fast in Ramadan on a cloudy day, thinking that evening had come and the sun had set. Then a man came to him and said: "O Commander of the Believers, the sun has appeared." Umar (may Allah be pleased with him) said: "The matter is a small one, and we did exercise our judgement." Imam al-Shafi'i (may Allah have mercy on him) says: He is to make up one day in its place.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8012
Ali bin Hanzalah (may Allah be pleased with him) narrates from his father: We were with Umar (may Allah be pleased with him) when a large bowl was brought in the month of Ramadan. The muezzin said: "The sun is still up." He said: "May Allah protect us from your evil! We did not send you to watch the sun; we sent you to call to the prayer." Then he said: "O people, whoever of you has broken his fast, making up a day is easy; otherwise, let him complete his fast."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8013
Ali bin Hanzalah (may Allah have mercy on him) narrates from his father, and his father was a friend of Sayyiduna Umar (may Allah be pleased with him). He says: Once in Ramadan I was with Sayyiduna Umar (may Allah be pleased with him); he broke his fast and the people broke their fast too. Then the muezzin went up to call the adhan and said: "O people, here is the sun; it has not yet set." Sayyiduna Umar (may Allah be pleased with him) said: "May Allah suffice us against your evil; we did not send you to watch for this." Then Sayyiduna Umar (may Allah be pleased with him) said: "Whoever of you has broken his fast, let him fast a day in its place."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8014
Bishr bin Qays narrates from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him): Once in Ramadan I was with Sayyiduna Umar (may Allah be pleased with him) in the evening, and it was a cloudy day. He thought that the sun had set, so Sayyiduna Umar (may Allah be pleased with him) drank and gave me to drink too. Then they saw it on the slope of the mountain, and Sayyiduna Umar (may Allah be pleased with him) said: "It does not matter; we will fast a day in its place."
The agreement of these narrations from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) on making up the fast is evidence that the narration of Zayd bin Wahb about not making it up is mistaken.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8015
Zayd bin Wahb (may Allah be pleased with him) says: Once we were sitting in the mosque of Madinah; it was Ramadan and there were clouds in the sky. We thought that the sun had set and that evening had come, so a large bowl of milk was brought out for us from the house of Hafsah (may Allah be pleased with her). Umar (may Allah be pleased with him) drank and we drank too. We had stayed only a short while when the clouds cleared and the sun appeared. Some of us said: We will make this day up. When this reached Umar (may Allah be pleased with him), he said: By Allah, we will not make it up; we did not commit this sin deliberately.
This narration contradicts the earlier narrations. Zayd is thiqah (trustworthy), but he is not safe from error. May Allah protect us from slipping and from mistakes by His vast mercy.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8016
Sayyiduna Shu'ayb bin Amr bin Sulaym (may Allah be pleased with him), who had reached the age of 115 years, says: We broke our fast with Sayyiduna Suhayb (may Allah be pleased with him), I and my father, in the month of Ramadan on a day of drizzle and clouds. While we were eating our evening meal, the sun appeared. Sayyiduna Suhayb (may Allah be pleased with him) said: "This was food given by Allah, so complete your fast until night, and make up one fast in its place."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8017