July 18 marked Nelson Mandela International Day, held to celebrate the 97th birthday and legacy of the former South African president.

In November of 2009, the United Nations declared July 18 "Nelson Mandela International Day" in recognition of his contribution to the culture of peace and freedom in South Africa and the world. "The General Assembly resolution A/RES/64/13 recognizes Nelson Mandela's values and his dedication to the service of humanity, in the fields of conflict resolution, race relations, the promotion and protection of human rights, reconciliation, gender equality and the rights of children and other vulnerable groups, as well as the upliftment of poor and underdeveloped communities," according to the United Nations's website.

Mandela, who died in 2013, was also famous for his name "Madiba." According to the Nelson Mandela Foundation site, "This is the name of the clan of which Nelson Mandela was a member. A clan name is much more important than a surname as it refers to the ancestor from which a person is descended. Madiba was the name of a Thembu chief who ruled in the Transkei in the 18th century. It is considered very polite to use someone's clan name."

To commemorate the anti-apartheid president's 67 years of humanitarian legacy, South Africans did community service and charity for 67 minutes on Saturday, according to the Christian Science Monitor. People from all over the world also memorialized the legacy of Madiba by tweeting with the hashtags #MandelaDay, #Time2Serve and #MakeEveryDayAMandelaDay. Here's how volunteers across the globe celebrated #MandelaDay with service, as featured on MTV.

Last July 18, 2014, Google created a logo to honor Mandela on his 96th birthday, as featured in a previous HNGN article. His inauguration speech on May 10, 1994 has also been memorialized as well. Brain Pickings's editor, Maria Popova, wrote an article about the timeless speech, saying, "We may have lost Nelson Mandela, unequaled patron saint of equality, peace, and human rights, but his spirit remains forever with us - a spirit that not only changed political history, but also tirelessly elevated humanity into a higher version of itself." 

Madiba's inauguration speech is available below in its entirety:

The Nelson Mandela Foundation keeps on encouraging people from all over the world to give 67 minutes of their time, no matter how small the action is, to changing the world for the better. The site has a "What Can I Do?" section devoted to specifying how anyone can help.