Messenger of Allah ﷺ said, "When night falls from this side and the day vanishes from this side and the sun sets, then the fasting person should break his fast."
قَالَ رَسُولُ اللَّهِ ﷺ إِذَا أَقْبَلَ اللَّيْلُ مِنْ هَا هُنَا وَأَدْبَرَ النَّهَارُ مِنْ هَا هُنَا وَغَرَبَتِ الشَّمْسُ فَقَدْ أَفْطَرَ الصَّائِمُ