Pillars & FiqhThe time for slaughtering begins after the Eid al-Adha prayer; whoever slaughters before the prayer, it does not count as valid for him, due to his ﷺ saying: «من ذبح قبل الصلاة فإنما هو لحمٌ قدّمه لأهله». According to the most correct view, it extends for four days: the day of Eid and the three days of Tashreeq, ending at sunset of the thirteenth day.
Source:حديث البراء (متفق عليه)؛ وفتوى ابن باز [خلاف: الجمهور ينتهي بغروب 12]

