The Prophet (peace and blessings be upon him) said:
"The Days of Tashriq (the 11th, 12th and 13th of Dhul-Hijjah) are days of eating, drinking and remembrance of Allah Almighty."
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 2689
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[حم م] عن نبيشة. الروض النضير ٢/٢٥٠.