Thanks for the explanation. 12:00 GMT is currently 08:00 EDT, and that's easy to reckon about. I did notice today, though, when the mobile app said "Last update 22 hours ago, next update in 23 hours 53 minutes", which implies a 46-hour update cycle, the local time would have been a bit after the 08:00 EDT update, and the news stories hadn't changed in the app. Indeed, stories I'd already clicked on were grayed out.
Presently, on the web version, it does say "next update soon", but it's currently 13:04 GMT, and it appears to be the same news stories as from hours before. I can imagine there might be some lead time on that 12:00 GMT update, but I did just want to call that out.