If you are not early on in the game, I would just let it play out. It is a possibility that they will release the kiddies in the future. But if your are just starting a new game when this occurred, I would suggest just starting a new game, but keep this one going to see if you can save it.
And as LadyCFII pointed out, your "keep-alive" battery could have caused the problem. If it did not keep your clock "going" while it was off, you could have had the wrong time when you turned your system back on. Then when you connected to the internet, it could have sync the system clock to the real time, thereby causing this problem. Just guessing. You could have your battery tested to see if it is still good.
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The VI