You need to make sure you're running a version that is compatible with what the servers are running. If you're running 1.7.5 and the server is at 1.7.7, then you need to get 1.7.7 too. Minetime should be updated 1.7.7, or at least allow players running that version to login, so I don't see where the issue might be.
Mojang Brought 1.7.6 out then brought out 1.7.7 and the server is not updated to 1.7.7 so Downgrade your MC to get on the server.