CentOS update breaks another thing – the logwatch perl timezone manipulation. The exact error message is:

ERROR: Date::Manip unable to determine TimeZone.
Execute the following command in a shell prompt:
perldoc Date::Manip
The section titled TIMEZONES describes valid TimeZones and where they can be defined.

You could fix it modify /etc/localtime. You could use tzconfig command line and follow its questions or:

cp /usr/share/zoneinfo/Europe/Rome /etc/localtime

If your localtime is different, you could choose your zoneinfo in /usr/share/zoneinfo/.

Referece: fullo.net