Horloges révolutionnaires (décimales)
(journée de 10h de 100 minutes de 100 secondes)
officiellement en vigueur du 5 octobre 1793 au 7 avril 1795

@credits

Decimal time is the representation of the time of day using units which are decimally related. This term is often used to refer specifically to French Revolutionary Time, which divides the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal seconds, as opposed to the more familiar standard time, which divides the day into 24 hours, each hour into 60 minutes and each minute into 60 seconds.

Decimal time was officially introduced during the French Revolution; the National Convention issued a decree on 5 October 1793. Although clocks and watches were produced with faces showing both standard time with numbers 1–24 and decimal time with numbers 1–10, decimal time never caught on; it was not officially used until the beginning of the Republican year III, 22 September 1794, and mandatory use was suspended 7 April 1795 (18 Germinal of the Year III), in the same law which introduced the original metric system.

For fun, if you want to compare the decimal and the duodecimal time…