According to the folk calendar - Astafy Windmill

The holiday got its name due to the fact that at this time a strong wind often rose, and Orthodox Christians on this day honor the memory of St Eustathius Placidas, who was one of the best Roman commanders On Astafyev Day, work began on the windmills Grains from the new harvest were used for grinding On October 3, it is customary to celebrate the holiday of millers from windmills