Adoption of the Gregorian calendar Julian to the Gregorian calendar. For example, in the article "The October (November) Revolution" the "Encyclopædia Britannica" uses the format of "25 October (7 November, New Style)" to describe the date of the start of the revolution. Other countries of eastern Europe, most notably Eastern Orthodox countries, adopted the Gregorian calendar in the 1910s or early 1920s. The last country of Eastern Orthodox Europe to adopt the Gregorian calendar for civil purposes was Greece, at the time under military administration following the 11 September 1922 Revolution, with Wednesday 15 February 1923 being followed by Thursday 1 March 1923. The Soviet
Lithuanian calendar month names on this artifact are expressed in symbols, based on natural phenomena and agricultural cycles. (i.e. the sidereal month was divided into three parts). The Julian calendar was used in the Grand Duchy of Lithuania; the Gregorian calendar was adopted by the Polish-Lithuanian Commonwealth in 1586, a few years after its promulgation in 1582 by Pope Gregory XIII. In 1800, following Lithuania's annexation by the Russian Empire, the Julian calendar again became the norm, although a part of ethnic Lithuania left of Nemunas River (Suvalkija) retained the Gregorian calendar (see Aleksotas). The Russian Revolution of 1917 re-instated the Gregorian