Sayyiduna Ali (may Allah be pleased with him) was asked: What is completing the Hajj? He said: Entering ihram from your own home.
The Shaykh said: The time of (the Treaty of) Hudaybiyah was in Dhu al-Qa'dah of the sixth year of the Hijrah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8706