You'll need a server with required functionality that runs the game logic. It's stuff that will get complicated quickly, and C2 might not be the most optimal tool for that sort of project. You could have an interface created in C2 that communicates with the server, which does most of the heavy lifting and calculations.
Edit: Just for the clock functionality, you could use AJAX/PHP to communicate with some service and grab a time stamp. But for true multiplayer you'd need a server.