A calico sits in its enclosure and suns itself in Hessen, Germany on May 28, 2021. The Opel Zoo presents a walk-in Madagascar aviary for caltas and varis. The primate species is native to Madagascar and is threatened with extinction. (Photo by Andreas Arnold/dpa)

First graders of a cadet's lyceum attend a ceremony to mark the start of the new school year in Kiev, Ukraine, September 1, 2015. September 1 marks the start of a new academic year for students in Ukraine.(Photo by Valentyn Ogirenko/Reuters)

A model takes photographs during the World Bodypainting Festival in Poertschach, Austria, July 1, 2016. (Photo by Heinz-Peter Bader/Reuters)

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)

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

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

A villager dries chillies on September 1, 2020 in Bijie, Guizhou Province of China. (Photo by VCG/VCG via Getty Images)

A full moon is seen behind buildings at night in Ashkelon, southern Israel on December 1, 2020. (Photo by Amir Cohen/Reuters)