Calendar reform the traditional fixed arithmetic Hebrew calendar, respectively. Calendar proposals that introduce a thirteenth month or change the Julian-Gregorian system of months often also propose new names for these months. New names have also been proposed for days out of the week cycle (e.g., 365th and leap) and weeks out of the month cycle. Proposals to change the traditional month and weekday names are less frequent. The Gregorian calendar obtains its names mostly from gods of historical religions (e.g., Thursday from Nordic Thor or March from Roman Mars) or leaders of vanished empires (July and August from the first Cæsars), or
Adoption of the Gregorian calendar 1 for 1868, "Taishō" 1 for 1912, "Shōwa" 1 for 1926, "Heisei" 1 for 1989, and so on. Still, this system has increasingly been replaced in popular usage by the "Western calendar" (西暦, "seireki") over the course of the twentieth century. Korea adopted the Gregorian calendar on 1 January 1895 with the active participation of Yu Kil-chun. Although the new calendar continued to number its months, there were multiple systems used to refer to its years: during the Joseon Dynasty, in 1895–97, its years were numbered from the founding of that dynasty, regarding 1392 as year one; then between 1897