IGT ending has changed to turning on Autosave during the Basilisk fight. This means you can quit at the start of the credits (the game won't let you pause after defeating the Basilisk until that point), so you don't have to wait 7 or 8 minutes to find out in-game time. It was originally done the other way so that pausing didn't interrupt the run, but it only takes 5 or 6 seconds to turn on Autosave so it's not a huge deal.