A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

A group of children run into a fountain on the South Bank on August 1, 2011 in London, England. Temperatures in the capital reached around 27 degress today and are expected to hit 30 degrees by Wednesday. (Photo by Dan Kitwood/Getty Images)

A baby hippopotamus lies next to its mother on the first day it was presented to the public at the Zoo Berlin zoo on November 1, 2011 in Berlin, Germany. The baby hippo was born at the zoo on October 23. (Photo by Sean Gallup/Getty Images)

Fireworks light up the skyline over Sydney Harbour during the midnight fireworks session as Sydney Celebrates New Year's Eve with the theme of “Time To Dream” on on January 1, 2012 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)

A woman holds up an umbrella and license plates, one that reads “love”, during violent protests between riot police and demonstrators in the Causeway Bay district of Hong Kong on October 1, 2019. The city observes the National Day holiday to mark the 70th anniversary of communist China's founding Strife-torn Hong Kong on October 1 marked the 70th anniversary of communist China's founding with defiant “Day of Grief” protests and fresh clashes with police as pro-democracy activists ignored a ban and took to the streets across the city. (Photo by Nicolas Asfouri/AFP Photo)

In this Thursday, March 28, 2019, photo, a “golden giant burger” is served at a restaurant of Hotel Grand Hyatt Tokyo in Tokyo. The $900 wagyu (Japanese-produced beef) burger was unveiled to commemorate the era change. What’s in a name? Quite a lot if you’re a Japanese citizen awaiting the official announcement Monday, April 1, 2019 of what the soon-to-be-installed new emperor’s next era will be called. It’s a proclamation that has happened only twice in nearly a century, and the new name will follow Emperor Naruhito, after his May 1 investiture, for the duration of his rule, attaching itself to much of what happens in Japan. (Photo by Kyodo News via AP Photo)

A model showcases designs by Metias as part of the LMFF Offsite Runway 1 show on day six of the 2011 L'Oreal Melbourne Fashion Festival at Peninsula Central Pier Docklands on March 19, 2011 in Melbourne, Australia. (Photo by Marianna Massey/Getty Images)

Model Adriana Sklenarikova Karembeu presents new “Pikolino” shoes at El Corte Ingles store on April 1, 2011 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)