WARSAW — It is 3:30 p.m. on a Saturday and the sun is already setting over Warsaw. The hours of daylight here are dictated by the tilt of the Earth, Poland’s position in the Northern Hemisphere and the time of year.

But the early time of the sunset is the result of something else. Poland’s fierce desire to be part of Europe after breaking through the Soviet Iron Curtain.

For decades, the Soviet Union was on permanent daylight saving time, its clock constantly racing ahead of the sun. The Poles did not want to be told by the Russians when the day would end. Even if it meant putting up with darkness in the afternoon, they would rather be on European time because it meant being part of the European Union.

But last week, Poland challenged the very notion of what it means to be part of the bloc when the country pushed ahead with controversial measures to overhaul its judicial system and essentially put the courts under the control of the governing party. The action set off unprecedented censure from the European Union.