In LR4, I selected several video clips that were showing the wrong capture date, then selected Edit Capture Date from the Metadata menu in the Library. I entered "1/1/1997 12:00:00 AM" and clicked Update. Instead of writing that date/time for each clip, LR wrote each one at a slightly different date/time, all around 12/26/1996. I can update the capture date for one clip without a problem, but selecting multiple produces this strange and very bad outcome. Haven't tested this with other media types in LR.