They set up schools but made very little progress in conversion, handicapped by dietary rules that prohibited popular local foods such as pork and shellfish, and that also banned tobacco, alcohol and kava.

Tonga lies to the east of the 180° meridian, but to the west of the International Date Line (IDL), in the time zone UTC+13:00.

[4][5] In the early years the insistence on eating only "clean" foods and abstaining from tobacco and alcohol were obstacles to conversion.

[9] Seventh-day Adventists became active in the South Pacific in 1886 when the missionary John Tay visited the Pitcairn Islands.

[10] On its first voyage, the Pitcairn visited almost every "white family" in the Tongan islands, and sold books worth more than $500.

[13] The SDA missionary Edward Hilliard, his wife Ida, and daughter Alta arrived at Nukuʻalofa on 30 August 1895.

[24] In September 1897 Doctor Merritt Kellogg and his wife Eleanor Nolan came to assist with the medical work.

[21] The Butz's tried to establish a permanent mission, but were mainly limited to working with the small papalagi (European) colony.

[14] In June 1899 the Pitcairn again visited, bringing a small prefabricated building that was used at first as a mission home and as a chapel.

[21] Maria helped when Queen Lavinia gave birth to Sālote Tupou III (13 March 1900 – 16 December 1965).

When he died in Haʻapai a visiting SDA minister officiated at his burial in 1903 after the Free Church, Wesleyans, Catholics and Anglicans all refused to give him a funeral.

[36] Some members of the royal family patronized the SDA school, but the church suffered from emigration and lapses.

[14] Stewart rebuilt the Falaloa school, which had been badly damaged by a hurricane, and started revival meetings in an effort to improve standards of worship.

[43] The school at Nuku'alofa was reopened with about forty pupils, and a government teacher from Australia joined the mission.

The first camp meeting was held in June 1922 at Nuku'alofa, attended by members of the Faleloa and Neiafu churches.

[44] Growth in the Tongan mission after the 1920s was largely due to converts among pupils at the SDA schools, especially those of Maggie Ferguson.

A group of students at Tonga College decided to worship at the nearby SDA church at Mangaia, and many of them joined the Adventists.

[46] During World War II (1939–45) the Seventh-day Adventists kept a low profile in Tonga and grew slowly.

[49] After the 1970s, growth in SDA membership in Tonga slowed sharply due to emigration and competition from other churches.

[citation needed] Students of Beulah College sat for the University Entrance exam for the first time in 1986.

Islands such as Samoa and Tonga were well to the east of this line, so the missionaries observed the Sabbath on the day sequence of the Western Hemisphere.

However, the Tonga islands used the same days as New Zealand and Australia, so the missionaries were observing the seventh-day Sabbath on Sunday.

[57][f] The tract by Adventist John N. Andrews entitled The Definitive Seventh Day (1871) recommended using a Bering Strait date line.

It was not until 1901 that White sent a letter to Kellogg but her reply did not answer the question, it simply stated it was not his task to solve the problem of the dayline.

[59] Time, circumstances and practice led to the 180° meridian being imposed by the Adventists as the IDL, and the SDA church in Tonga observes the Sabbath on Sunday.

Historian, Kenneth Bain, in his 1967 book, The Friendly Islanders, claimed that SDA adherence to the 180 degree meridian is a face saving compromise which their pioneer missionaries searched out because the nation had strict Sunday laws.

[4][5] In 1995, the time zone of Kiribati was changed so Adventists on the Phoenix and Line Islands observe Sunday.