Ok, I have stalked this thread before and there are a lot of answers but they are over time. I thought i'd accumulate the information into one post (Including Billon). Here are the dates:
1846 - French Guiana (French rule, billon, french francs may still be used)
1883 - Argentina (One of the first to abandon silver)
1889 - Paraguay (Only circulation silver Issue)
1895 - Haiti
1909 - Bolivia
1919 - Norway
1920 - British West Africa (Gambia, Sierra Leone, Ghana Nigeria, Cameroon)
1923 - Denmark (Commemorative)
1924 - Costa Rica, Lichtenstein
1925 - Mongolia
1930 - Bhutan (Indian Silver kept circulating after this date)
1931 - Soviet Union (and successor States)
1932 - Latvia, Chile
1933 - Hong Kong (Under Britain), Estonia
1936 - Nicaragua
1937 - Bulgaria, Afghanistan
1938 - Brazil, Lithuania, Yugoslavia, San Marino
1939 - Poland (Definitive), Albania
1940 - Cyprus (Under Britain)
1942 - Thailand (definitive), British Palestine (Israel/Palestine), Tunisia
1943 - Ireland (definitive)
1944 - Slovakia and Czechoslovakia, Romania, French Indochina (Now Cambodia, Laos and Vietnam), DR Congo (Belgium), Seychelles
1945 - Philippines, Indonesia (under Netherlands), Guyana (under UK), British Malaya (today Malaysia, Singapore), Fiji (Under UK), Papua New Guinea (UK)
1946 - UK, Belize, Luxembourg (definitive), Mauritius, Myanmar and Pakistan and Bangladesh(British India), New Zealand (Definitive), British East Africa (Tanzania, Kenya, Uganda, Somalia and for a short time, Aden Colony and South Arabian Protectorates).
1947 - Hungary (definitive), Ethiopia
1948 - Turkey (definitive)
1949 - New Zealand (Commemorative), China/Taiwan (Republic Restrike + provinces and Republic on Taiwan), Curacao (Netherlands)
1950 - Somalia (under Italy)
1951 - Iran
1952 - Guinea - Bissau, Lebanon
1953 - Cuba, Cape Verde (Under Portugal), Tibet, Columbia, South Rhodesia (present Zimbabwe)
1954 - El Salvador
1955 - Saudi Arabia, Belgium, Angola
1957 - Sri Lanka
1958 - Honduras
1959 - Syria
1960 - Turkey (Commemorative), Iraq
1962 - Liberia, Oman, Sao Tome & Principe
1963 - Thailand (Commemorative), Dominican Republic, Yemen
1964 - Bermuda, Guatemala, Luxembourg (Commemorative), Timor Leste,
1965 - Venezuela, Morocco, Greece
1966 - Australia, Ireland (Commemorative), Japan, Monaco , Mozambique, Suriname, Vanuatu
1968 - Canada, Netherlands (definitive), Finland, Nepal
1969 - Switzerland, South Africa, Biafra (Modern Nigeria), Uruguay (definitive, see below), Canada (error)
1970 - USA and Panama (Billon), Netherlands Antilles, Egypt, Spain (definitive), Italy and Bahamas
1971 - Sweden, Peru
1972 - India
1973 - Austria (not including MTTs as they stopped being regular circulation)
1974 - Germany, Macau (under Portugal)
1976 - Portugal
1978 - Holy See (Vatican)
1984 - Uruguay (possible non circulating)
1988 - Poland (commemorative, unlikely to have circulated)
1995 - Mexico (definitive), Hungary (commemorative)
1996 - Netherlands (Commemorative)
2001 - Spain, France, Portugal (Commemoratives non-euro, unlikely to have circulated)
2007 - Mexico (Commemorative)
Uruguay, Portugal still mint commemoratives that are technically for circulation. Face value often exceeds bullion. MTT is still used as a trade coin in some parts of Africa and Asia, but for many reasons is not included. Malaysian Provinces and Kingdoms have issued silver dirhams, recently, which see some limited circulation. Canada issued a small number of commemorative 5 and 10 dollar pieces in 1973 that are listed in the Charlton Guide as circulating though never did.
I have made this as comprehensive as possible, let me know if anything has to change.





