Until the
October Revolution, the official time in Moscow corresponded to GMT+02:30:17 (according to the longitude of the Astronomical Observatory of
Moscow State University). In 1919 the
Council of People's Commissars of the RSFSR introduced the system of time zones in the country, and Moscow was assigned to the second administrative time zone, equal to GMT+02:00. Other zones east of the 37.5° meridian to
Arkhangelsk,
Vologda,
Yaroslavl,
Kostroma,
Ivanovo,
Vladimir,
Ryazan,
Tula,
Lipetsk,
Voronezh and
Rostov-on-Don were also included in the second belt. In accordance with the 16 June 1930 Decree of the
Council of People's Commissars, the
Decree Time was introduced by adding one hour to the time in each time zone of the USSR, so that Moscow Time became three hours ahead of
Universal Time. Until 2011, during the winter, between the last Sunday of October and the last Sunday of March,
Moscow Standard Time (MSK, МСК) was three hours ahead of UTC, or UTC+03:00. In the summer, Moscow Time shifted forward an additional hour ahead of Moscow Standard Time to become
Moscow Summer Time (MSD), making it UTC+04:00. In 2011, the Russian government proclaimed that
daylight saving time would be observed all year round, thus effectively displacing
standard time — claiming health concerns attributed to the annual shift to-and-fro DST. On 27 March 2011, Muscovites set their clocks forward for a final time, effectively observing MSD, or UTC+04:00, permanently. On 29 March 2014, after the
annexation of Crimea by the Russian Federation, the
Republic of Crimea and the city of
Sevastopol — two
federal subjects established by Russia on the
Crimean Peninsula — switched their time to MSK on 30 March 2014 (from UTC+02:00 with DST to UTC+04:00 with permanent DST). On 1 July 2014, the State Duma passed a bill partially repealing the 2011 change, removing permanent DST and putting Moscow Time from 26 October 2014 on permanent UTC+03:00 and thus back to standard time. == Usage ==