The flag of the Netherlands

The Dutch flag is flying. The picture was taken by J.A.H. de Haan in the period of 1945-1947. Every year at 8 pm on 4 May, the Dutch commemorate civilians and soldiers who have died in the Kingdom of the Netherlands or elsewhere in the world since the outbreak of the Second World War, both in war situations and in peacekeeping missions, with two minutes of silence. Prior to this homage, a commemorative service is held at the National Monument on the Dam square in Amsterdam, with speeches and the laying of wreaths. On May 4th, Remembrance Day, flags everywhere in the Netherlands are at half-mast as a sign of mourning from 6 p.m. until sundown. The next day, the flag is hoisted again everywhere to celebrate Liberation Day.

Source :
https://beeldbankwo2.nl/nl/beelden/?mode=gallery&q=J.A.H.%20de%20Haan&page=1&record=e87d4474-025a-11e7-904b-d89d6717b464&view=horizontal
https://www.holland.com/global/tourism/activities/events/remembrance-day.htm