"Metric Time" is a misnomer. The unit of time in the metric system of measurement has always been the conventional second - 1/86400 of the rotational period of the earth.
However, during the French revolution, the French. in excessive eagerness to rid themselves of everything associated with the monarchy, introduced the concept of "Decimal Time". The day was to be divided into ten hours, each hour into 100 minutes and each minute into 100 seconds. This scheme was popularized briefly at the time of the revolution but never caught on outside France. Later, other schemes were tried including dividing the day into 100 hours with decimal divisions into minutes and seconds.
A more detailed description can be found in Wikipedia...
https://en.wikipedia.org/wiki/Decimal_time
Decimal Time did last long enough for the clockmakers to make clocks that displayed it. This image from the above article shows one...
Attachment 37664
If you ever run across one in a garage sale, buy it no matter the price; they're worth a small fortune in the antique market due to their extreme rarity.