As the title says, if decimal time was used at least in France and some parts of Europe. (Along the French republican calendar)
a) How could the decimal time zones be made? (a sort of decima GMT time zones) and their equivlante in GMT.
b) And also if instead of degrees (0°-360°), the gradian/gon (0°-400 gradians) was used to create the time zones.
c) and more challenging the Meridian of Paris is the prime meridian.
That is to say world that has two time keeping standards (GMT and French Metric)