I live in Moscow. And use timezone Europe/Moscow. When I sync owncloud to android over davdroid - it’s all OK! But if I sync android to owncloud - event will make with Moscow time plus one hour. I tried with other app - all ok.
I used a version of DavDroid June/July 2015. I’ve updated via F-Droid. Actually I didn’t do anything else. Then the 401 sync-error came up automatically.
Since nobody else complaint about this authentication problem , I guess it’s a rare bug and probably not worth investigating.