I had a similar issue some months ago, though it was not just logging into WC... all my subscriptions had run out as well. I wasn't sure why at first, but when i finally checked the date it was 1 Jan 2066. Yeah, that's what I thought.. WTF!!!!
I have a feeling that it had something to do with the monthly MS updates because no other changes were made to my system. I resolved the issue by using system restore to reset the date prior to the updates. Strange, to say the least... the updates were redownloaded/installed the following day but the date was still correct afterwards.