I threw the Jamarat before Zawwal on the eleventh day of Dhul-Hijjah out of ignorance, as I thought Zawwal was Fajr. Do I owe a دم (sacrificial offering) or is it sufficient to throw them next year, and what is the ruling on my Hajj?

The stoning (ramy) on the Days of Tashreeq is not valid except after zawal (midday). Whoever stones before zawal must repeat it. However, if one stones before zawal out of ignorance, there is no sin upon him, but he must sacrifice a sheep in the Haram and distribute its meat to the poor as an atonement for neglecting this obligation. It is permissible to appoint an agent for this, even by phone.