Question: When did the currencies of the country east of Swaziland first come into circulation?

full_context: Document 1: Economy of Eswatini: Eswatini, Lesotho, Botswana, Namibia, and the Republic of South Africa form the Southern African Customs Union (SACU), where import duties apply uniformly to member countries. Eswatini, Lesotho, Namibia, and South Africa also are members of the Common Monetary Area (CMA) in which repatriation and unrestricted funds are permitted. Eswatini issues its own currency, the lilangeni (plural: emalangeni), which is at par with the South African rand.
Document 2: Eswatini: Swaziland is a developing country with a small economy. Its GDP per capita of $9,714 means it is classified as a country with a lower-middle income. As a member of the Southern African Customs Union (SACU) and Common Market for Eastern and Southern Africa (COMESA), its main local trading partner is South Africa. Swaziland's currency, the lilangeni, is pegged to the South African rand. Swaziland's major overseas trading partners are the United States and the European Union. The majority of the country's employment is provided by its agricultural and manufacturing sectors. Swaziland is a member of the Southern African Development Community (SADC), the African Union, the Commonwealth of Nations and the United Nations.
Document 3: Mozambique: Mozambique (), officially the Republic of Mozambique ( or "", , , , ), is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini (Swaziland) and South Africa to the southwest. The sovereign state is separated from the Comoros, Mayotte and Madagascar by the Mozambique Channel to the east. The capital of Mozambique is Maputo (formerly known as "Lourenço Marques" from 1876 to 1976) while Matola is the largest city, being a suburb of Maputo.
Document 4: Eswatini: At no more than 200 kilometres (120 mi) north to south and 130 kilometres (81 mi) east to west, Swaziland is one of the smallest countries in Africa. Despite its size, however, its climate and topography is diverse, ranging from a cool and mountainous highveld to a hot and dry lowveld. The population is primarily ethnic Swazis whose language is siSwati. They established their kingdom in the mid-18th century under the leadership of Ngwane III; the present boundaries were drawn up in 1881. After the Anglo-Boer War, Swaziland was a British protectorate from 1903 until 1967. It regained its independence on 6 September 1968.
Document 5: Euro: The changeover period during which the former currencies' notes and coins were exchanged for those of the euro lasted about two months, until 28 February 2002. The official date on which the national currencies ceased to be legal tender varied from member state to member state. The earliest date was in Germany, where the mark officially ceased to be legal tender on 31 December 2001, though the exchange period lasted for two months more. Even after the old currencies ceased to be legal tender, they continued to be accepted by national central banks for periods ranging from several years to indefinitely (the latter for Austria, Germany, Ireland, Estonia and Latvia in banknotes and coins, and for Belgium, Luxembourg, Slovenia and Slovakia in banknotes only). The earliest coins to become non-convertible were the Portuguese escudos, which ceased to have monetary value after 31 December 2002, although banknotes remain exchangeable until 2022.
Document 6: South Africa: South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by 2,798 kilometres (1,739 mi) of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Swaziland (Eswatini); and it surrounds the kingdom of Lesotho. South Africa is the largest country in Southern Africa and the 25th - largest country in the world by land area and, with close to 56 million people, is the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status. The remaining population consists of Africa's largest communities of European (white), Asian (Indian), and multiracial (Coloured) ancestry.
Document 7: Cape Verdean escudo: In mid-1998 an agreement with Portugal established a pegged rate of 1 Portuguese escudo = 0.55 Cape Verdean escudo. Since the replacement of the Portuguese escudo with the euro, the Cape Verdean escudo has been pegged to the euro at a rate of 1 EUR = 110.265 CVE. This peg is supported by a credit facility from the Portuguese government.
Document 8: Coins of the Indian rupee: The move towards decimalization was afoot for over a century. However, it was in September, 1955 that the Indian Coinage Act was amended for the country to adopt a metric system for coinage. The Act came into force with effect from 1 April 1957, after which anna and pice denominations were demonetised. The rupee remained unchanged in value and nomenclature. It, however, was now divided into 100 'paisa' instead of 16 annas or 64 pice. Effective from 30 June 2011, all coins in denominations of 25 paisa and below were officially demonetized.
Document 9: Mozambican metical: The metical (MZM) replaced the escudo at par on 16 June 1980. It was divided into 100 centavos. The metical underwent severe inflation. After the revaluation of the Romanian leu, the metical briefly became the least valued currency unit, at a value of about 24,500 meticais per USD, until the Zimbabwean dollar took the title in late August 2005.
Document 10: Zimbabwean dollar: The first Zimbabwean dollar was introduced in 1980 and replaced the Rhodesian dollar at par. The initial ISO 4217 code was ZWD. At the time of its introduction, the Zimbabwean dollar was worth more than the US dollar in the official exchange market, with 1 ZWD = 1.47 USD, although this did not reflect the actual purchasing power it held. As a result, in both the official and parallel markets, the currency's value eroded rapidly over the years, and by July 2006, the parallel market value of the Zimbabwean dollar fell to Z $1,000,000 = GB £1.
Document 11: Spanish peseta: The peseta was replaced by the euro in 2002, following the establishment of the euro in 1999. The exchange rate was 1 euro = 166.386 pesetas.
Document 12: South Africa: South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded on the south by 2,798 kilometres (1,739 mi) of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans; on the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and on the east and northeast by Mozambique and Swaziland; and surrounds the kingdom of Lesotho. South Africa is the largest country in Southern Africa and the 25th - largest country in the world by land area and, with close to 56 million people, is the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status. The remaining population consists of Africa's largest communities of African (black), European (white), Asian (Indian), and multiracial (coloured) ancestry.
Document 13: Salvadoran colón: The colón was the currency of El Salvador between 1892 and 2001, until it was replaced by the U.S. Dollar. It was subdivided into 100 centavos and its ISO 4217 code was SVC. The plural is colones in Spanish and was named after Christopher Columbus, known as Cristóbal Colón in Spanish.
Document 14: Eswatini: A small, landlocked kingdom, Swaziland is bordered in the North, West and South by the Republic of South Africa and by Mozambique in the East. Swaziland has a land area of 17,364 km2. Swaziland has four separate geographical regions. These run from North to South and are determined by altitude. Swaziland is located at approximately 26°30'S, 31°30'E. Swaziland has a wide variety of landscapes, from the mountains along the Mozambican border to savannas in the east and rain forest in the northwest. Several rivers flow through the country, such as the Great Usutu River.
Document 15: Cape Verdean escudo: After independence on 5 July 1975, notes were issued for 100, 500, and 1000 escudos on 1 July 1977. The next series of notes was introduced in 1989 and consisted of 100, 200, 500, 1000 and 2500 escudos.
ground_truth: 16 June 1980
sub_queries: What nation is to the east of Swaziland? Answer: Mozambique
when did the currencies of Mozambique first come in circulation Answer: 16 June 1980