Moi Day was a public holiday in the Republic of Kenya observed annually on October 10. The holiday was established in 1988 to commemorate the tenth anniversary of Daniel arap Moi’s presidency, which began in 1978 following the death of the nation's first president, Jomo Kenyatta.
During the era of President Moi's administration, the day was characterized by national celebrations, military parades, and speeches focusing on the government's achievements. However, following the promulgation of the new Constitution of Kenya in 2010, Moi Day was omitted from the list of recognized national holidays, as the new law sought to reduce the number of holidays and shift the focus away from personality-based celebrations.
In November 2017, the High Court of Kenya reinstated the day as a public holiday. Justice George Odunga ruled that the removal of Moi Day was a violation of the Public Holidays Act, noting that as long as the Act had not been formally amended by Parliament to remove the holiday, it remained legally binding. The court did not dictate how the day should be celebrated but affirmed its status as a day of rest.
In subsequent years, the Kenyan government moved to rename the holiday to distance it from its original association with President Moi. In December 2019, the cabinet approved the renaming of October 10 to "Huduma Day" (Swahili for "Service Day"), intended as a day for national service and volunteerism. In 2020, the name was officially changed through legislative amendments.
In 2023, the government under President William Ruto renamed the October 10 holiday to "Utamaduni Day" (Culture Day) to emphasize the celebration of Kenya’s cultural diversity and heritage. In 2024, the designation was changed again to "Mazingira Day" (Environment Day) to encourage national efforts in environmental conservation and climate change mitigation. Despite these changes in name and purpose, the date remains a public holiday in the Kenyan calendar.