Have a small report - have a production/return time a little bit greater then 8000 days.
How to reproduce:
1. Android TV-box without any kind of battery (don't save system time)
2. Reboot TV-box.
3. Launch Fallout Shelter (before then TV-box receive time from network - synced will be with small delay 1..5 minute)
4. Change game state (like revoke dweller or finish+start new production).
5. Leave Fallout Shelter
6. Laund game again, after clock sync (be sure - time must be right)
7. Check dweller or production building time
Purposed way to fix:
time = time > 7 ? 7 : time;
My TV-box: DRACO AW-80, Android 4.4.2
Thanks!