What are the valid days for the Hajj sacrifice (hady)?

The time for the Hajj sacrifice (hady) begins after the Eid prayer on the 10th of Dhul Hijjah and extends through sunset on the 13th of Dhul Hijjah (the last day of Tashreeq). This is the view of the majority of scholars. The Prophet (peace be upon him) said: 'All the days of Tashreeq are days of slaughter' (narrated by Ahmad, graded sahih by al-Albani in Irwa' al-Ghalil 1141). Sheikh Ibn Baz stated: 'The time for sacrifice is four days: the day of Eid and the three days of Tashreeq' (Fatawa Ibn Baz, vol. 16). Slaughtering at night is permissible according to the strongest opinion, though daytime is preferred. The Permanent Committee ruled that the sacrifice must be done within these days and cannot be delayed beyond them without a valid excuse.