Nazi dictator Adolf Hitler greets supporters at a May Day gathering in the Olympic Stadium, Berlin. (Photo by Keystone). 1st May 1938

A reveller walks through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

Students from the University of St Andrews jump into The North Sea, as a good luck tradition before exams start on the East Sands in St Andrews, Fife, Scotland on May 1, 2018. (Photo by Derek Allan/Alamy Live News)

A protester dressed as a clown holds an umbrella over a Swiss police officer on a motorbike during a May Day demonstration in Zurich, Switzerland on May 1, 2017. (Photo by Arnd Wiegmann/Reuters)

The Acura Stage area is flooded after a storm dumped several inches of rain on the second Saturday of the New Orleans Jazz Fest at the Fair Grounds, Saturday, April 30, 2016. (Photo by David Grunfeld/NOLA.com/The Times-Picayune via AP Photo)

An animal advocate lays in fake blood in a replica of a meat package with a label that reads “meat” during a protest “The meat is murder” in the Bulgarian capital Sofia on May 8, 2016. (Photo by Nikolay Doychinov/AFP Photo)

Kyrgyz men on horseback compete during their traditional game of “Oodarysh” during the celebrations of the 90th anniversary formation of the Chui region in the village of Kuntu some 20 kms from Bishkek on May 27, 2016. (Photo by Vyacheslav Oseledko/AFP Photo)

Two Brits enjoy Saturday night in Leeds, United Kingdom in bank holiday on May 1, 2021, as number of coronavirus cases and deaths keep decreasing in the UK. The government today reported seven new coronavirus deaths and a further 1,907 infections. (Photo by Nb press ltd)