"“I favor a unified calendar for the whole world, just as I am in favor of one currency for all coun- tries and a world auxiliary language such as Esperanto for all peoples.” or sometimes “I am for the same calendar for the whole world, as I am for the same currency for all the people and a world auxiliary language like the Esperanto for all the people.” (only one source is not esperantist, and the only source that gives a date is esperantist and doesn’t name the involved recipient of the said letter)"