I'm not sure how long this has been going on, but I just noticed that every now and then the day and month get reversed in the Customer Since field. Example: I had to customers register yesterday and the date displays as Jun 10, 2015 3:35:53 PM. I had two more customers register today and it shows Nov 6, 2015 2:56:52 PM. Should I be worried about this? should I call them and ask them about the stock market at that point in time? I don't see that this should cause a problem, unless maybe someone who hasn't registered until November can't access their accoun until then? But I don't know...
Any ideas why this might be happening?
There is some discussion on this bug in a StackExchange post here: http://magento.stackexchange.com/questions/33242/magento-1-8-1-customer-grid-date-display-bug/
I have this problem in EE 1.13 as well, it doesn't seem to affect anything aside from display the dates wrong.