Have you tried uninstalling and reinstalling? We have heard no other reports of this issue following this release.
I'm seeing the same issue as well. Everything was working OK with Geocaching 2.2.x and even 2.3 when I first installed it. I decided to wipe my data and reload GC 2.3. Now, I get a wrong date/time error when I try to login even though my phone's settings are correct.