It is real time, and it isn't. As you probably know you're able to see the games in progress on the ticker during a player-controlled game, but to do that the engine sims all CPU-controlled games on the schedule before you start the on-field game. Then the ticker uses the in-game time of day to reflect what would have already been played out in the simmed games, and from that it's able to show that the games look like they're in progress.
As others said already, this illusion falls apart with multi-team control, as fewer/no games from the day will be simmed prior to starting your game. So there's less/no info to show on the ticker.
So, it's a fake real-time, but a pretty convincing one under normal circumstances. And in a single team franchise it might as well be real time unless you spoil yourself by backing out to the "today's games" schedule after the sim.
Edit: Also, In-game stadium scoreboards operate under the same principle - and have been doing so even before the ticker was introduced into the game.