The confusion stems from the fact the user is asked for both timezone (GMT offset) and DST flag. A user in NSW, during summer, could enter any of these combinations (together with the wristwatch time):
Timezone +10, DST=YES
Timezone +10, DST=NO
Timezone +11, DST=YES
Timezone +11, DST=NO
Two of them are correct, and it's fairly straightforward to work out which those are. It can still be confusing during setup in the field.
I sidestep the issue altogether, by entering UTC time, timezone +0 and DST=NO at all times of the year
