The concept of decimal time, wherein a day is broken down into multiples of 10, was first suggested more than thirty years prior when French mathematician, Jean le Rond d'Alembert, argued in 1754 ...

In a decimal system, we could divide each day into ten “decidays”. A deciday would comprise 10 “centidays” or 100 “millidays” – each milliday would be 1,000 “microdays”, and so on .