Umar bin Khattab reported,

The Messenger of Allah ﷺ said, "When night approaches from this side, day departs from that side, and the sun has set, the fasting person has broken his fast."

Azami 11965

Sahih

عن عمر بن الخطاب قال

قال رسول الله ﷺ: إذا أقبل الليل من ها هنا، وأدبر النهار من ها هنا، وغربت الشمس فقد أفطر الصائم.

الأعظمي 11965صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Virtues of Surah Baqarah
Section
His saying, "It has been made permissible for you the night preceding fasting to go to your wives. They are clothing for you and you are clothing for them. Allah knows that you used to deceive yourselves, so He turned to you in forgiveness and pardoned you. So now have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread of Fajr. Then complete the fast until the night. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits of Allah, so do not approach them. Thus does Allah make clear His verses to the people."
Numbering
Jami al-Kamil 11965 (2nd edition)
Azami 11965