Dear Mark, here are the timezones on my openSUSE system:
mainframe:~ # readlink -f /etc/localtime
mainframe:~ # cat /etc/sysconfig/clock
They were not changed recently.
However, I feel there may be something related here. Please see the screenshot of the Visits menu.
Is it OK that when I start the visit on 30.01.2017, the date on the left reads as 29.01.17?