Fiqh-us-Sunnah Volume 5, Hajj and ‘Umrah, Fiqh 5.109A.

Section : When to Return from Mina.

The three schools of Islamic law hold that the pilgrims must return from Mina to Makkah before the sunset of the 12th of Zhul-Hijjah after throwing the pebbles.

The Hanafi school, however, is of the opinion that pilgrims may return to Makkah betore the dawn of the 13th of Zhul-Hijjah. Leaving after sunset is, however, disliked for it is against the sunnah. but one who does so incurs no penalty.