ICJ President Peter Tomka will read the judgment during a public session in the Japanese Room on the first floor of the Peace Palace (right) at The Hague, Netherlands. (The court's usual Palace venue, the Great Hall of Justice, is undergoing renovation.)
If you can't make it to The Hague, you can watch delivery of the judgment live online, at 3 p.m. Hague time (that's 9 a.m. New York time).
As IntLawGrrls have written in posts available here, the dispute is part of a long-running, multi-forum litigation respecting Hissène Habré, the former Chadian dictator who's been in exile in Senegal since 1991. Specifically at issue in the ICJ case, Questions relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal), is interpretation of the Convention Against Torture, to which both Belgium and Senegal belong.
Check the court's multimedia webpage on Friday if you'd like to see the session online -- as this 'Grrl is sure to do, having had the opportunity, while at The Hague this past March, to watch Senegal present its case -- en français, though the written judgment will be available in English as well as French.