I know it sounds like a cool thing at first, but it just makes the game pointless. The dwellers wont train and the resource stations still produce food, water and energy, but it doesnt decrease. The game just started being boring after a while and i was hopeing it got fixed.

Rush all your rooms and stop messing around with the system date/time. That should take care of the resource bug.

I don't know if it will help with your training, if it doesn't you are just going to have to wait until the date time matches the last time you leveled up your training. (It also has been rumored that waiting is one of the causes of the permanent crash bug).