Decimal Time: How the French Made a 10-Hour Day (2013)

* But in 1793, the French smashed the old clock in favor of French Revolutionary Time: a 10-hour day, with 100 minutes per hour, and 100 seconds per minute. This thoroughly modern system had a few practical benefits, chief among them being a simplified way to do time-related math: if we want to know when a day is 70% complete, decimal time simply says “at the end of the seventh hour,” whereas standard time requires us to say “at 16 hours, 48 minutes.” The French manufactured clocks and watches showing both decimal time and standard time on their faces (allowing for conversion and confusion).

Source: mentalfloss.com