timetool uses the config file /etc/sysconfig/clock generated by timeconfig and assumes that if the hw clock is UTC, /etc/sysconfig/clock contains the regular expression ".*GMT.*". But unfortunately, what is expected is the string "UTC="yes"" when the hw clock is UTC. Because of this wrong regexp, timetool does not work well when the hw clock is UTC.
This is fixed in the currently shipping timetool.