and later.... I got curious,
Set hwclock manually, then set system clock manually to same date and time (today). each showed the correct time when 'data' or 'hwclock' commands entered.
Set system time to equal hwclock -s for completeness.
then rebooted and time came back correctly (well CET, it is an hour out, but I was not bending my head around that right now, the aim to see if it survives reboot or power off without the loss / gain of an hour or so).
then powered off for less than a minute and the time came back correctly.
then powered off for 5 minutes and the time (and date) comes back correctly
Does this help explain the "funny things" where some folks have it OK and others not?
Is there any testing you would like for modify hwclock or system clock times and reboots to help? Let me know.
edit... thinking a bit more.... do we need to wait for several midnight boundaries to see if it still works after a day change??