The day took its name from the church calendar on the day of honoring the memory of St. Polycarp of Smyrna, who became a Christian bishop in the 1st century. The wedding period was coming to an end, so unmarried and unengaged girls walked around upset. That’s why the day was called “sour girls.” By watching the magpies on Polikarpov's day, they determined the coming weather: if they hid under the roof, the residents prepared for heavy snowfall, headed into the forest and waited for the arrival of warmth.