My system clock is an hour off since we started daylight savings time several days ago. In the past the adjustment was made automatically. I tried to reset the clock from the date/time module, but that didn't help. I suspect that since the starting date of DST has changed, KDE hasn't been updated to account for that. Rebooting doesn't help. A related problem is that there's no obvious way to get to the date/time module as superuser.
You must update the timezone-data package so that the operating system can get the current start/end dates for the daylight saving time. That is not controlled by any KDE software at all as far as I know.
Using synaptic, I was unable to find any package named timezone-data.
The problem now seems to have cured itself. I'm guessing that the time program's notion of when Daylight Savings Time begins is one week off, since it's now just one week after the actual time change.
(In reply to comment #3) > The problem now seems to have cured itself. I'm guessing that the time > program's notion of when Daylight Savings Time begins is one week off, since > it's now just one week after the actual time change. Probably, that is what usually happens when the timezone-data package is not up to date. I do not know which name Ubuntu uses for that package. The tar ball name is something like tzdata2011n.tar.gz, maybe the package is called tzdata.