It was narrated from Abu Hurairah that the Prophet (ﷺ) said:
"Whoever catches up with a prostration of Subh before the sun rises, then he has caught up with it; and whoever catches up with a prostration of 'Asr before the sun sets, then he has caught up with it." (ID)
English reference (ID): Vol. 1, Book 6, Hadith 551 (ID)
Arabic reference (ID): Book 6, Hadith 555 (ID)