Abu Dawud

(1) "Yawm al-Nahr" refers to the 10th of Dhu al-Hijjah. Although sacrifice (qurbani) can also be performed in the subsequent days, the day of sacrifice is specifically the 10th of Dhu al-Hijjah. The Messenger of Allah (sallallahu alayhi wa sallam) sacrificed one hundred camels on Yawm al-Nahr itself.

(2) On Yawm al-Nahr, the time for stoning (rami) begins from sunrise; whenever one gets the opportunity, even if unable to do so during the day, one may perform it at night. On the remaining days, the time for rami begins after the sun passes its zenith (zawal al-shams). Furthermore, on the remaining days, all the jamarat are stoned.

1:
This contains evidence that the Sunnah is that, except for the Day of Sacrifice (Yawm al-Nahr, the 10th of Dhu al-Hijjah), the stoning (rami) on the other days—the 11th and 12th—should be performed after the sun has passed its zenith (after zawal). This is the opinion of the majority (jumhur). Ata and Tawus have declared it absolutely permissible before zawal, and the Hanafis have allowed concession for stoning before zawal on the day of departure (yawm al-nafr). There is no evidence from the actions or statements of the Prophet (sallallahu alayhi wa sallam) in support of the view of Ata and Tawus. However, the Hanafis have deduced their opinion from a narration (athar) of Ibn Abbas (radi Allahu anhu), but that narration is weak. Therefore, the opinion of the majority is the one to be relied upon.

628 Benefits and Issues:
➊ On the first day, the pebbles should be thrown before the sun passes its zenith, and on the remaining days, after the sun has passed its zenith.
➋ If on the tenth day one is unable to throw the pebbles before the sun passes its zenith, then they should be thrown after the sun has passed its zenith on the same day.