The Order of Time

by Carlo Rovelli

For centuries, we have divided time into days. The word “time” derives from an Indo-European root—di or dai—meaning “to divide.” For centuries, we have divided the days into hours.37 But for most of those centuries, however, hours were longer in the summer and shorter in the winter, because the twelve hours divided the time between dawn and sunset: the first hour was dawn, and the twelfth was sunset, regardless of the season, as we read in the parable of the winegrower in the Gospel according to Matthew.38 Since, as we say nowadays, during summer “more time” passes between dawn and sunset than during the winter, in the summer the hours were longer, and the hours were shorter in wintertime.