They list the other semi-final as starting at 6 PM and then Malvern Prep's game starting at 8 PM. That should be about right if there is no OT in the first game.
MP faces Phelps tonight. Should they win, they likely would meet #1 seed Westtown. Westtown has only lost one game to a PA team this year - and that was to Philly power Neumann-Goretti, which may be PA's top team.