The French are implementing a new way of formatting time that is based on the decimal system. In this new system, days would be 10 hours long, an hour would have 100 minutes, and a minute would have 100 seconds. This is ridiculous because we have gotten so used to the "old" way of recognizing time that this shift will be too jarring for people to get acclimated to.
The day is dictated by the amount of time that the earth takes to rotate. It would make no sense for the day to be decided this way. Mathematically it does not seem possible. Also it would be confusing whenever the French had to interact with anyone from another country.
Trying to create a 10 hour day would be ridiculous. As of right now, the sun sets and darkness is here for half of our current days. Making a day 10 hours would mean that some days would be all light and some days would be all darkness. It is just too big a change to adjust to.
The conversion of time to a decimal system would not work for many reasons. The cost of converting clocks and watches and machinery would be prohibitive. Plus the education of our citizens to accept a new system of measuring time would be confusing and disruptive from the current time keeping system.