solstice

päivänseisaus One of the two points in the ecliptic at which the sun is furthest from the celestial equator. This corresponds to one of two days in the year when the day is either longest or shortest.
2010, Capt Sp Meek, https://books.google.com/books?id=ZNrtnH9kvYYC&pg=PP8&dq=solstice&hl=en&sa=X&ved=0CD4Q6AEwBji0AWoVChMI6YaS8uWsxwIVkiqICh32vgDdv=onepage&q=solstice&f=false The Solar Magnet

The point at which the sun is nearest to the south pole we call the winter solstice, and the opposite point, the summer solstice.