The Messenger of Allah ﷺ said: “When night Comes from here and day departs from here, the fasting person may break his fast.ʿ (Using translation from Aḥmad 383)  

عَنِ النَّبِيِّ ﷺ قَالَ «إِذَا جَاءَ اللَّيْلُ مِنْ هَاهُنَا وَذَهَبَ النَّهَارُ مِنْ هَاهُنَا فَقَدْ أَفْطَرَ الصَّائِمُ»  

[Machine] I heard Abdullah ibn Abi Aufa saying, "We were with the Prophet ﷺ on a journey when he said to a man, 'Descend and milk (your camel).' The man said, 'O Messenger of Allah, the sun has set.' The Messenger of Allah ﷺ said to him, 'Descend and milk (your camel).' The man said, 'O Messenger of Allah, the sun has set.' Then he said again, 'Descend and milk (your camel).' So the man descended and milked (his camel) and the Prophet ﷺ drank. Then he said, 'When you see the night has come from this direction,' and he pointed with his hand towards the horizon, 'the one who is fasting should break his fast.' Abu Abdur-Rahman said, 'This hadith is narrated by Asim ibn Umar and the hadith of Ibn Abi Aufa are both authentic.'"  

سَمِعْتُ عَبْدَ اللهِ بْنَ أَبِي أَوْفَى يَقُولُ كُنَّا مَعَ النَّبِيِّ ﷺ فِي سَفَرٍ فَقَالَ لِرَجُلٍ «انْزِلْ فَاجْدَحْ» قَالَ الشَّمْسُ يَا رَسُولَ اللهِ ثُمَّ قَالَ لَهُ رَسُولُ اللهِ ﷺ «انْزِلْ فَاجْدَحْ» قَالَ الشَّمْسُ يَا رَسُولَ اللهِ ثُمَّ قَالَ «انْزِلْ فَاجْدَحْ» فَنَزَلَ فَجَدَحَ فَشَرِبَ النَّبِيُّ ﷺ ثُمَّ قَالَ «إِذَا رَأَيْتُمُ اللَّيْلَ قَدْ أَقْبَلَ مِنْ هَاهُنَا وَأَشَارَ بِيَدِهِ إِلَى الْأُفُقِ فَقَدْ أَفْطَرَ الصَّائِمُ» قَالَ أَبُو عَبْدِ الرَّحْمَنِ وَحَدِيثُ عَاصِمِ بْنِ عُمَرَ وَحَدِيثُ ابْنِ أَبِي أَوْفَى صَحِيحَانِ