Does the time difference between Moscow and Nairobi change during the year?

No. Both cities keep the same local time all year.

When is the best time to call Nairobi from Moscow?

Between 09:00 and 17:00 in Moscow, which is 09:00 to 17:00 in Nairobi.

Moscow and Nairobi are on the same local time. This gap is the same all year — neither city shifts its clocks relative to the other.

Moscow

Russia

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Nairobi

Kenya

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A 9-to-5 day in each city overlaps for 8h. That is 09:00–17:00 in Moscow, which is 09:00–17:00 in Nairobi.

City	Time zone	UTC offset
Moscow · Russia	Europe/Moscow	UTC+3
Nairobi · Kenya	Africa/Nairobi	UTC+3

What is the time difference between Moscow and Nairobi?: Moscow and Nairobi are on the same local time. This gap is the same all year — neither city shifts its clocks relative to the other.
Does the time difference between Moscow and Nairobi change during the year?: No. Both cities keep the same local time all year.
When is the best time to call Nairobi from Moscow?: Between 09:00 and 17:00 in Moscow, which is 09:00 to 17:00 in Nairobi.