I just realized this while I was adding some box codes to the Switch database. If a game already has a release date attached to it, say for example December 7,2018, and then I go and add a box code, check the "save to all box", and save the change, the date automatically changes to eliminate the day. So the date in the database becomes just December 2018. There have been games that I was positive I put a day in for when it was released and I went back only to see it wasnt there so this seems to be whats happening. I havn't noticed it happening with any other info Ive changed/added just the box codes.

Nice catch there.

I can confirm this bug - I just tested it by adding / modifying a game code, and sure enough it removed parts of the release date in the database.