Muhammad bin Ishaq narrates: The Messenger of Allah (peace and blessings be upon him) set out on Friday after praying the Friday prayer, and by morning he was in the pass of Uhud. Then the two sides met on Saturday, the fifteenth of Shawwal, in the year 3 AH.
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2916