Some progress has been made.

I managed to calculate the number of Days, Hours, Minutes and Seconds
elapsed since the reference date (01/01/2000 00:00:00)
from the DoubleWord seconds counter reading.

So far I can display the correct time from the iButton reading.

Next steps will be:
- calculation of Year, Date and Day of Week.
- A "Set Clock" Routine.
- automatic DST adjustment.

Your Input is still appreciated.

regards