The crazy kids of the French Revolution decided that, while everything was being overthrown, it might be a good time to get on with implementing the whole metric malarkey that Leibniz had been banging on about for so long.
And there was a bit of resistance, but on the whole, the people of France had plenty to be protesting about, and their pitchforks were mostly engaged elsewhere. And it looked like the whole thing would go ahead. It was a pretty sensible idea, after all. Dividing everything up into tens. We have ten fingers, after all.
Except then some smartarse decided that since they were doing metric measurment, they should really do metric time as well. And that didn't go down so well.
Suddenly, midnight was 10 o'clock. Midday was 5 o'clock. There were 100 seconds in a minute, 100 minutes in an hour. Oh, and they started the years again from 0.
So if they'd kept it, and we'd adopted it along with the rest of the metric system, today would be Decadi, 30th Prairial, 216. And it would be 5:65, instead of 2:35.
Needless to say, it didn't really catch on, and was abandoned after six months.