Jami` at-Tirmidhi 698
جامع الترمذي#698SahihUmar bin Al-Khattab narrated that:The Messenger of Allah said: "When the night advances and the day retreats, and the sun is hidden, then the fast is to be broken
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Bashar Awad MaaroufSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 8:17