At 3:00 a.m. local time on Sunday clocks will be changed to 2:00 a.m.
The changeover will begin with Russia's easternmost territory of Chukotka and move westward through eleven time zones to the enclave region of Kaliningrad on the Baltic Sea. Most of Europe will also change their clocks, although North America will wait another week.
With the shift back it will get light earlier in the morning and darker earlier in the evening, as the onset of winter makes for short, dark days.
Most computers will automatically adjust to the time change, but clocks and household appliances that show the time will have to be adjusted manually.
Most countries north of the Tropic of Cancer change to summer time around the start of the northern hemisphere spring to extend daylight further into the evening, although the practice is rare in Asia.
Medical opinion is mixed on how harmful or beneficial the change can be.