Gospel Day is a public holiday observed in Tuvalu on the Monday after the second Sunday in May. This day commemorates the arrival of Christianity to the archipelago in the 19th century, initiated by Elekana, a deacon from the Cook Islands, who began proselytizing after landing on Nukuaelae in 1861. The first European missionary, A. W. Murray, arrived in Tuvalu in 1865, and by 1878, Christianity had been established on each island. The national church, known as the Congregational Christian Church of Tuvalu, gained independence from the London Missionary Society in 1969 and follows a congregational organization and Calvinist doctrine. While the majority of Tuvalu's population identifies as Christian, there are also various other faith groups present, including Seventh-day Adventists, Roman Catholics, and atheists, with the constitution guaranteeing freedom of religion.