I noticed that one of the Debian Wheezy installs (dual booted with FreeBSD) was showing the wrong time, that is one hour behind BST. The hardware clock on this machine was set to UTC already, as preferred by FreeBSD. I thought the settings I had discovered earlier (here and here) would fix the issue, but that thought was incorrect.
The UTC=yes"
setting in /etc/defaults/rcS
is no
longer honoured; the timezone setting of the hardware clock is now
defined in /etc/adjtime
(as mentioned in this email).
The file contents of /etc/adjtime
look something like:
-0.230775 1406712073 0.000000 1406712073 LOCAL
Note the LOCAL value; this needs to be changed to UTC to indicate that the hardware clock is set to UTC. How this became set to LOCAL in the first place, I don't know. Probably some mistake during the original install.