1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

An Airbus A400M military aircraft lands at the ILA Berlin Air Show in Schoenefeld, south of Berlin, Germany, June 1, 2016. The Aerospace Exhibition at Schoenefeld Airport near Berlin takes place from June 1 till 4. (Photo by Fabrizio Bensch/Reuters)

A Cambodian villager rides a buffalo during the Pchum Ben festival, the festival of death, at Vihear Suor village in Kandal province on October 1, 2016. Thousands of Cambodians descended on the small village northeast of the capital on October 1 to cheer on the annual water buffalo race that marks the end of the 15-day festival for the dead. (Photo by Chor Sokunthea/AFP Photo)

Actors, clowns and mime artists celebrate “Humor Day” in St Petersburg on April 1, 2022. April 1 is also referred to as “April Fool’s Day” and is a time for playing pranks in the country. (Photo by Anatoly Maltsev/European Press Photo Agency)

A demonstrator is detained during May Day rallies in Santiago May 1, 2013. (Photo by Ivan Alvarado/Reuters)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

Artwork by Ruth Bellotti & Steve Rosewell called “Soldier Scale 1:1” is seen at the 2008 Sculpture by the Sea launch at Mark's Park, Bondi on October 15, 2008 in Sydney, Australia. (Photo by Gaye Gerard/Getty Images)

A boy sleeps in a hammock while his mother works at a brick kiln on the outskirts of Yangon February 1, 2015. (Photo by Soe Zeya Tun/Reuters)