What is the ruling on one who, out of forgetfulness, threw the pebbles about fifteen minutes before their proper time (zawal)?

Summary:

Whoever throws Jamrat al-Aqabah before Zawwal (midday) owes a compensatory sacrifice (dam), and if unable to offer it, then he must fast for ten days. This is because the preponderant opinion is that of the majority, who deem throwing (the pebbles) before Zawwal invalid during the Days of Tashreeq. They based their argument on the Prophet's (peace be upon him) throwing after Zawwal and his saying: "Learn your rituals from me." Also, the Prophet (peace be upon him) was never given a choice between two matters except that he chose the easier of them, as long as it was not a sin. If throwing before Zawwal were permissible, the Prophet (peace be upon him) would have done so due to the ease it would provide for people.