Computer shut down and reset date and time

Hi! I have a 13 inch Macbook Pro that I bought before going to college in the summer of 2012.

Last march, I spilled water on the computer and had the logic board replaced. Then, about three or four weeks ago, the display got messed up and Apple once again replaced my logic board and my display (this time, I hadn't done anything to the computer, something had gone wrong internally).

I'm currently studying abroad in the Czech Republic, and a few times now, my computer has randomly shut down when I move it (always when it is plugged in and charging). It's happened about 4 times now. Most recently (about 20 minutes ago), the computer immediately turned off when I unplugged it from power and when it powered back up, it had reset my date and time to December 21st, 2011.

There has been no trauma to the computer at all, and other than that, it has been running totally normally.

Thanks in advance.