# Time and Its Measure: Historical and Social Implications
## 2 The Social Implications of the Measurement of Time
10-day weeks) and in the unnatural denial of circadian rhythms, \"_The respect that all the principles command for the customs and habits of the Peoples and for those that affect public worship has restored the use of the common era with the new constitution\"_[7]. Clocks with ten-base dials (Figure 4) were immediately eliminated, although in Paris, for many years, a decimal clock remained in operation in the market square. In France, another attempt was made in 1897, when the Commission de decimalisation du temps, created by the Bureau des Longitudes, proposed a compromise of retaining the 24 h day but dividing each hour into 100 decimal minutes and each minute into 100 s. The plan did not gain acceptance and was abandoned in 1900. A similar attempt was repeated in recent times when [PERSON] tried to upset working times with a production organization based on only two shifts of ten hours each (very favorable for the employers). But, just as quickly, he was challenged by the trade unions in the FCA factory in Serbia who saw serious risks to the level of attention of workers (and, therefore, to their safety). The ability of \"social time\" to express a greater meaning in the collective perception than the astronomical one, so as to become a reference, is also found in commonly used expressions such as \"_immediately after the world war_\" or \"_see you later the football match_\". Similarly, expressions such as \"_for a semester_\", \"_for a working day_\" and \"_for the duration of Lent_\" represent references to generally understandable lengths of time while varying independently of each other, without any mention of astronomical phenomena. The radicalization of some social customs linked to time can also be found in the summer time convention. The proposal was first advanced in Paris by [PERSON], one of the American \"founding fathers\", in his essay _An Economic Project to Lower the Cost of Light_, published in the _Journal de Paris_ in 1784, but it fell on deaf ears. It was reconsidered and implemented only in 1916, in wartime, when energy saving became important, not only in the United Kingdom but also in Italy and other European countries. In reality, the desired result, an increase in the number of hours of daylight for leisure and free time, could have been achieved simply by moving the working hours from 8:00 to 4:00 p.m. But the designation \"9:00 to 5:00 p.m.\" has become so deeply ingrained in our economy that it has even been considered preferable to shift the hourly units in the twenty-four-hour cycle. The existence within the human body of cadences or circadian rhythms has been confirmed by the studies of three US scientists ([PERSON], [PERSON] and [PERSON]) who were awarded the Nobel Prize for Medicine [7]. The problems relating to the measurement of \"relative time\" are as follows:  
* Legal, as commercial transactions require certainty in the determination of time. (In international financial dynamics, electronic transactions that are concentrated in the last seconds of the closing of the stock exchanges require maximum attention! );  
Figure 4: Clock with ten-base dials. International, as GPS service (Figure 5) is considered \"strategic\" for governments, so much so that the service connected to the traceability of the signal cannot be interrupted, even in the event of a strike. Regarding the first problem, in order to enact an international convention establishing how time should be measured, when the day should begin and end or what length an hour might be, in 1884, the Greenwich meridian was chosen as the prime meridian of the world during the International Meridian Conference. In the late 19 th century, 72% of the world's commerce depended on sea charts, which used Greenwich as the prime meridian, and this made it the center of world time. The division into time zones is vital for international organizations, but, sometimes, it risks being compromising due to the operational difficulties that it entails.