The government planned to voluntarily evacuate four million people—mostly women and children—from urban areas, including 1.4 million from London. It expected about 90% of evacuees to stay in private homes, and conducted an extensive survey to determine available space. Detailed preparations for transporting them were developed. A trial blackout was held on 10 August 1939, and when Germany invaded Poland on 1 September a blackout began at sunset. Lights would not be allowed after dark for <answer>almost six years</answer>, and the blackout became by far the most unpopular aspect of the war for civilians, more than rationing.:51,106 The relocation of the government and the civil service was also planned, but would only have occurred if necessary so as not to damage civilian morale.:33
How long were lights not allowed on after dark?
almost six years