I had a similar situation with the same versions of openSUSE and KDE, also on 64-bit hardware and set up for dual boot.
But I was dual booting MS-Windows VISTA.
AFAIK, Microsoft Windows effectively expects the hardware clock to be “local time”.
openSUSE was configured to treat the hardware clock as UTC, but also use NTP ( Network Time Protocol ) to get the correct time from time hosts on the Internet.
So if I used Windows and then openSUSE, Windows would set the hardware clock to UTC-6, then openSUSE would interpret the UTC-6 as UTC, and get the wrong idea about the current time. The panel clock would be set to the wrong time.
Then openSUSE would use NTP to get the correct time. The panel clock would then be updated to the correct time.
Once I changed the openSUSE configuration to treat the hardware clock as Local time, the problem was solved.
I don’t know how Mint interprets the hardware clock value, but you might want to check to see if it differs from your openSUSE configuration. That might be the cause of the problem. If so, you may find that your system logs have confusing times in them as well.