26 days
They’re using what’s called “feature flags” or “feature toggles.” It lets the software team work faster and safer: ship inactive code updates to clients, then gradually, remotely turn them on to make sure the changes work and be able to quickly go back without requiring another app update if something goes wrong.
They’re quite powerful and effective if used correctly. Very standard practice these days.
Could be. I have no idea how it’s implemented in this specific device/app. It might immediately resume tracking the duration when it boots (or you opened the app before correcting the time) and cancels the stopwatch when it finds the start time is seemingly in the future. If I still had my iPod Touch, I’d try to find out — decent nerd sniping opportunity.