Each MojoLock has an internal clock that is set when you first add the lock to your account.  If the front and back of the lock are disconnected for an extended period of time, if the batteries run out, if the batteries are removed from the lock for an extended period of time, or if you change the batteries, the clock may need to be reset in order for the MojoLock to function properly.  You can reset the clock by locking or unlocking the MojoLock via Bluetooth from the ShowMojo mobile app.