The Court of Cassation set the date as soon as Berlusconi's lawyers deposited their appeal Tuesday, an almost unheard of quick turnaround for Italy's notoriously slow justice system.
The stakes of the ruling are incredibly high for Berlusconi, who has dodged legal woes for much of his two decades in politics but now faces the specter of being barred from holding public office for five years if his sentence is upheld.
In May, an appeals court in Milan upheld Berlusconi's tax fraud conviction and four-year prison sentence. He was convicted in a scheme that involved inflating the price his Mediaset media empire paid for TV rights to U.S. movies and pocketing the difference. Berlusconi has said he did nothing wrong and has accused Milan magistrates of pursuing politically motivated cases against him.
The stakes of the appeal are also high for Italy: Berlusconi's support of Premier Enrico Letta's government is crucial to its survival. His center-right forces are allied with the Democratic Party in a grand coalition, and although Berlusconi holds no governmental posts, he remains influential. Letta declined to comment Tuesday on the justices' decision other than to say he didn't think the outcome would affect his government.
Berlusconi's attorney, Niccolo Ghedini, said Tuesday that the court's decision to schedule a hearing during its summer session was unprecedented for a case such as this. And he disputed the purported reason behind it, saying the statute of limitations on one charge wouldn't expire until Sept. 15, and another not until September 2014.
"The significance of the decision is obvious," he said in a statement.
Berlusconi's political heir, Angelino Alfano, sarcastically praised the high court for its remarkable efficiency in scheduling the date, noting that it usually takes 200 days for an appeal to be heard in Italy. Alfano, who was justice minister in Berlusoni's last government, said he hoped lesser-known Italians would benefit from such efficiency.
The Mediaset case isn't the only one hanging over the ex-premier. Last month, Berlusconi was sentenced to seven years and banned from politics for life for paying an underage prostitute for sex during infamous "bunga bunga" parties and forcing public officials to cover it up. He denies wrongdoing and is appealing that verdict as well.
Given Berlusconi's age and other circumstances, it's unlikely that he would serve any prison time if his sentences are upheld by the high court. In Italy, sentences are only considered final after two levels of appeals are exhausted.