Hi, I am not sure if this has been mentioned before but the French Annuaire pour l'an ...., publié par le Bureau de Longitudes, published annually since 1797 and available from the Gallica website, usually contains a detailed section on the legal time in France, French colonies and dependencies and elsewhere. This annual section, which of course is the most detailed for France and the French speaking part of the world with references to the appropriate official government publications, can be very useful for checking the historical references in the tz database or adding new entries. The easiest way to access these volumes is by using the weblinks at the bottom of the Wikipedia page discussing the Connaissance de Temps https://en.wikipedia.org/wiki/Connaissance_des_Temps Rob van Gent