Comment 3 for bug 1907907

Well then its a bug in Qt WebEgine not using your system locale. It
might be possible to workaround it by using the system format directly.
What does running the follwoing in a command prompt return:

calibre-debug -c "from PyQt5.Qt import *; app = QApplication([]); print(QLocale.system().timeFormat(QLocale.ShortFormat))"