Is it permissible for the one in a hurry to cast the pebbles on the 12th of Dhul-Hijjah before Fajr?

It is not permissible to stone the Jamarat on the Days of Tashreeq—including the Day of Hastening (Yawm al-Ta'ajjal)—except after Zawwal (midday). This is the view of the majority of scholars. Abu Hanifah, in one narration from him, held the view that it is permissible before Zawwal but after sunrise. However, no one has held the view that it is permissible before dawn.