Comment # 1 on bug 930008 from Wolfgang Bauer

Please use YaST to setup the NTP time server.

This KDE control module doesn't work like you probably would expect anyway.
It just sets the time once when you click on OK/Apply, it doesn't actually
configure any time server in the system.

Btw, it doesn't crash here on 13.2, but I do know about lots of crash reports
upstream at KDE's bugzilla.
See https://bugs.kde.org/show_bug.cgi?id=242648 e.g. which even contains
similar backtraces as you posted.

As KDE4 is nearing its end-of-life those crashes won't be fixed I suppose.
In Plasma5 this has been solved by preferring the use of systemd's timedatectl
to apply the settings.

Thanks for your bug report, but let's close it as UPSTREAM.
Although probably WONTFIX would be a more fitting resolution.