UPDATE: "Due to issues with the instance servers crashing, we're going to reschedule the Icecrown Gunship Battle encounter for a future time," Daelodev said.
Icecrown Citadel raid tests are currently scheduled to be held tonight and tomorrow on both the North American and European test realms. Players on the US PTRs get to fight Festergut tonight at 7 p.m. EDT and participate in the Icecrown Gunship Battle tomorrow, Oct. 22, at 7 p.m. EDT. European players will battle Rotface tonight at 7:30 p.m. CEST and get their own gunship battle tomorrow at 7:30 p.m. CEST. Only normal difficulties will be tested, but 10- and 25-player raids will be available.
Remember, testing schedules can change at a moment's notice and things can break on the PTR at any time. Keep an eye on both the North American and European test realm forums for the latest raid testing schedule. More information on the Frozen Throne raid dungeon can be found on the preview page.