well... your understanding is what i would have expected from the system as well... but.. the system was designed in late 80-s, early 90-s... so, it is a little bit different...
you need to set the clock as close to the actual time as possible, and the system will sync the minutes only, not the hours... from my testing, the minutes need to be set within 4 minutes from actual time...
sorry if this disappointed you...
