Physikalisch-Technische Bundesanstalt

PTB invites the general public to its premises on 14 July 2012. We recall that following the French Revolution (14 July 1789) the idea of a new decimal time counting was born. The calendar law dated 4 Frimaire II (24 November 1793) prescribed a decimal division of the day, to be used from 22 September 1794 onwards. A day should from then on consist of 10 hours of 100 minutes each. As it was expensive to acquire new clocks with the new type of display, decimal time was abandoned again already on 7 April 1795.

As the division of the day in 10 hours of 100 minutes needed getting used to it, watches showing the two time systems simultaneously were produced. Its hands show 14:00 and at the same time 05:38 decimal time. The shortest (hour-) hand points to 14 and close to VI, respectively, the median points to the decimal minute 83, the longest points to the traditional minute 0 or 60.