1 May is celebrated internationally as "Labour Day". This goes back to the American Federation of Labor, which decided in 1888 to celebrate 1 May as a social holiday in 1890. Since 1918, this day has been a public holiday in many countries. In addition to numerous trade union demonstrations, many festivals and May Day celebrations usually take place on this day.
For this reason, flags are displayed on public buildings throughout Germany, including the town hall of the municipality of Rüdersdorf near Berlin.
Source: Tim Reckmann / PIXELIO