The Messenger of Allah ﷺ said, "Two months of celebration are never deficient, Ramadan and Dhul-Hijjah."
حدثنا أبو سلمة يحيى بن خلف البصري حدثنا بشر بن المفضل عن خالد الحذاء
قال رسول الله ﷺ شهرا عيد لا ينقصان رمضان وذو الحجة
Graded muttafaq alayhi (agreed upon).It was also narrated by Muslim in the Book of Fasting, chapter on explaining the meaning of his saying, ﷺ "Two months of Eid do not decrease," hadith no. 1089, and by Bukhari, in the Book of Fasting, chapter "Two months of Eid do not decrease," hadith no. 1912, from the hadith of Khalid Haddan, with the same wording.