sleeping time in the ISS

Oct 27, 2020
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are the russian cosmonauts sleep when there is night in russia and the american astronauts sleep when there is night in the US so that they will be awake during the day in there country ?
It may be helpful to note that they are on the GMT standard, so when we see them in the evening in the U.S., they are flying over us a day (by their clock) later since they are usually after midnight when we might be, say, 8 or 9 pm.