These
are the main steps in the official adoption of the metric system. It was
sometimes actually implemented after a rather long period.
"(opt)"
stands for optionnal, indicating that the use of the metric system is
legally authorized, but not compulsory.
1792
: Southern Netherlands, that became French departments.
1803
: Helvetian Republic.
1810
: The rest of the Netherlands, incorporated to France.
1820
: Kingdom of the Netherlands, that became independant. The system was kept
in Belgium when it became independant in 1830.
1836
: Greece (opt).
1839
- 1844 : Réunion, Senegal, French Guiana, Algeria, Martinique, Guadeloupe.
1848
- 1849 : Chile, Spain, Dominican Republic.
1852
- 1857 : Portugal, Colombia, Monaco, Mexico, Venezuela.
1861
- 1865 : Italia, Brazil, Peru, Uruguay, Argentina, Romania, Ecuador.
1866
: United-States (opt).
1868
: Bolivia, Switzerland.
1871
- 1875 : Germany, Austria, Czechoslovakia, Yugoslavia, Hungary,
Liechtenstein, Norway.
1878
- 1888 : Sweden, Costa-Rica, Cuba, French Africa, Finland, Bulgaria.
1893
: Japan (opt).
1893
: United-States - the yard and the pound are defined as metric units.
1894
- 1895 : Cameroon, Tunisia.
1897
: United-Kingdom (opt).
1899
: Russia (opt).
1905
- 1911 : Angola, British Guinea, Mozambique, Philippines, Denmark, Iceland,
San Marino, Guatemala, Honduras, Malta, Nicaragua, El Salvador, Zaire,
French Indo-China.
1918
- 1919 : USSR, Poland.
1920
- 1927 : India (opt), Haiti, South Africa (opt), Indonesia, Morocco,
Thailand, Togo, Afghanistan, Libya.
1929
: China.
1931
- 1939 : Irak (opt), Tunisia, Iran, Lebanon, Syria, Egypt.
1947
- 1959 - United-kingdom, United-States, Canada, Australia, New-Zeland, South
Africa- they decided jointly to adopt unified values for the yard and the
pound, which are defined as metric units.
1960
- 1963 : Irak, Australia (opt), Kuwait, Saudi Arabia, Ethiopia, Nepal.
1965
: United-Kingdom.
1967
- 1969 : South Africa, Kenya, Uganda, Pakistan, Tanzania, Ireland,
Singapore, Bahrain, Botswana, New-Zeland, Rhodesia, Swaziland.
1970
- 1975 : Australia, Canada, Gibraltar, New Guinea, Sri Lanka, Trinidad and
Tobago, Zambia, Bermuda, Guiana, Malaysia, Nigeria, Cyprus, Fiji, Ghana,
Somalia, Barbados, Jamaica, Nauru, Tonga.
1976
- 1977 : Gambia, Hong-Kong, Malawi, Sierra Leone.
1995
: United-Kingdom - the EEC compels the country to give up its own measures
for the metric system.