´It was narrated from Abu Hurairah that:` The Messenger of Allah said: "Whoever catches one Rak'ah of the 'Asr before the sun sets, then he has caught it, and whoever catches one Rak'ah of the Subh before the sun rises, then he has caught it."
Hadith ReferenceSunan Ibn Majah / The Book of the Prayer / Hadith: 699
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:بخاري ومسلم