On 6/11/20 4:59 AM, Michael H Deckers wrote:
[https://gallica.bnf.fr/ark:/12148/bpt6k2022333z/f2]... There is no mention in the legal texts of how the change is to be effected (let alone that legal time would stop for some time).
Yes, the crucial text there is: "A partir de la nuit du 10 au 11 mars 1911, à minuit, l’heure de tous les bureaux de poste, télègraphe et télèphone est celle du temps moyen de Paris, retardée de neuf minutes et vingt et une secondes." which Google Translate renders as: "From the night of March 10 to 11, 1911, at midnight, the time of all post offices, telegraph and telephone is that of Paris average time, delayed by nine minutes and twenty-one seconds."
Hence, the old definition of legal time applied until just before it took the value 1911-03-11T00:09:21, and the jump in legal time was from 1911-03-11T00:09:21 to 1911-03-11T00:00:00.
I wouldn't go quite that far, as the law doesn't specify how the transition should occur. Last week I would have said the law was consistent either with a transition from 00:00:00 to 23:50:39 or with a transition from 00:09:21 to 00:00:00. The other reports we've seen, though, suggest that it was common to implement the law by stopping the clock for 9 minutes 21 seconds at midnight. Here's a quote from the Washington Herald, March 11, 1911: "Paris. March 10. Starting exactly at midnight to-night, time was annihilated in France for the space of 9 minutes and 21 seconds. On the stroke of the hour all the clocks in the republic were stopped for the time indicated, in order to comply with the law making the time here the same as in all places with a radius 15 degrees, and in which the time is regulated from Greenwich, England. "All railway trains, if on time, were held up and those which were behind schedule schedule were required to make up the difference. Owing to the change in time an interesting question has arisen. It is questionable if a child that is born and dies with in the lapsed time will really had lived. This point i s puzzling the legal talent." There's a similar story in the Washington Times of the same date, headlined "Stop Clocks in France So Time Can Catch Up". I got these two stories from the Google Books entry for the book "Henri Poincaré: A Biography Through The Daily Papers" (2013), as Poincaré was involved in the effort to move France to GMT.
That does not imply that legal time had stopped, it just indicates how these clocks were adjusted. Other clocks (such as clocks on churches and pocket watches) would certainly have been adjusted in a less time-consuming manner.
Yes, that sounds right. Still, it does appear that, at least according to US press accounts, common practice in France was to stop the clocks.