I did some testing to see how the in game timer gets its times for "Time played as character" and here's what I found after some quick testing:
-The only times I could find during which the in game timer completely stopped running (other than when you pause), for any and all characters, was
- After a mission fail which isn't the result of a death of the character you're playing as. The timer continued to run until the mission failed screen showed the keys/buttons in the bottom right. Before these appear, it's still running. When you press one and the game gets going again, the timer starts up again. (milliseconds - however long you take to input a key after you're able to)
- After a death of the character you're playing as. If you're not on a mission and die, the timer seems to stop running the moment you die and stays idle until the fade in occurs (6-8 second pause). 2a. When you're on a mission and die, the timer stops running the moment you die and stays idle until you make the necessary input to trigger the next fade in. (~7 seconds?) 2b. Continuing from 2a, a mission section skip seems to leave the timer idle for a few more seconds, depending on the load.
-The stats menu found on the in game social club menu (press your Home key to access this) doesn't update until you save the game with either a save, autosave, or quicksave.
-The in game timer will sometimes run for multiple characters, at the same time, e.g., at some point after triggering the cutscene at the car during Prologue, the timer will be running for both Michael AND Trevor.
-The in game timer starts running for Michael the moment you start a new game (during the loading screens)
-The in game timer will run in real time during slow motion (I only tested the slow mo while holding ALT for character switching, but I assume it works in the same way for all slow motion moments)
-The in game timer will continue to run for whatever character you're using when you're holding ALT and the character switch menu is up. The moment you select a different character, the in game timer will instantly begin timing for the character you're switching to (during camera lift off and descent) and will stop timing for the previous character (Tested the required switch during Prologue and a typical switch out of mission)
-The timer definitely continues running during "some" cutscenes (not sure about moments of loading between cutscenes), and I'm not sure if there are some cutscenes where it doesn't run at all, but it was running during Michael's burial scene for ONLY Trevor's stat. (As I said previously, at some point before this, it was running for both Michael and Trevor during a cutscene)
-The in game timer never stops running during taxi interaction, even during the black screen when you trip skip.
-The timer continues running during shopping screens and I'd assume during web browsing as well (though I didn't test web browsing)
