The Messenger of Allah ﷺ used to throw the pebbles at the Jamarat once the sun had passed its zenith.
حدثنا أحمد بن عبدة الضبي البصري حدثنا زياد بن عبد الله عن الحجاج عن الحكم عن مقسم
كان رسول الله ﷺ يرمي الجمار إذا زالت الشمس
Grading, [Sahih], and Ibn Majah narrated it in "The Rites, Chapter on Throwing the Pebbles During the Days of Tashriq," hadith no. 3054, from the narration of Hakam with this wording, at length, and its chain is daif, and it has corroborating narrations, see hadith no. 894.