If you get the message "There is a problem with your system clock.", that's because of app/scripts/services/timecheck.coffee. So you can check up to four days, but after that, it gets you.

saved state hacking

The saved state is loaded from app/scripts/services/session.coffee, partiuclar the part about "LZString.decompressFromBase64".

To decode it in Linux:

(note: that isn't finished, it doesn't seem to want to decode)
(this is the javascript library that's used)