The clock settings are in the programming so there isn't much we can do about the clock. SMF just has some bugs. For me it is off by 1 hour 20 minutes. It bugged me enough that I fixed mine. It might already have a time offset that is wrong also. You can fix it on your individual profile though.
Go to profile, modify profile, look and layout there you will see a time offset field. If you are 20 minutes behind you need to enter .333 in the box then hit change profile at the bottom. If you are 20 minutes ahead you would enter -.333. You can adjust it a little one way or the other, then watch the clock up by your name to see if it is correct.
If you can't get it fixed and it really bugs you, let me know and I will try to fix it for you.