| before 22 May 1972 |
Island of Ceylon :: (from 7 Jul 1956) Śrī Laṃkā (ශ්රී ලංකාව) |
| 17 May 1946 |
the Ceylon (Constitution) Order in Council, 1946, is made on 15 May 1946 and came into operation in parts, starting from 17 May 1946 (Statutory Instruments, 1946, Volume I, pp. 2248-2277) [1][2] |
| 4 Feb 1948 |
Ceylon became an independent state in accordance with an act passed by the Parliament of the United Kingdom (House of Commons on 20 Nov 1964; House of Lords on 10 Dec 1964; received Royal Assent on 10 Dec 1947; effective on the date [4 Feb 1948] appointed by the Ceylon Independence (Commencement) Order in Council 1947 made on 19 Dec 1947) (Public General Acts, 1947, Volume II, pp. 1953-1958; Statutory Instruments, 1947, Volume I, Part I, p. 204) |
| 7 Jul 1956 |
Sinhala is recognized as the sole official language in accordance with an act passed by the Parliament of Ceylon (assented to on 7 Jul 1956) (Ceylon Government Gazette, No. 10,948, 7 Jul 1956, Supplement, Part II–Legal) |
| 22 May 1972 |
the Constitution of Sri Lanka (Ceylon) is adopted and enacted by the Constituent Assembly on 22 May 1972 |
| 22 May 1972 - 7 Sep 1978 |
Śrī Laṃkā Janarajaya (ශ්රී ලංකා ජනරජය) | Republic of Sri Lanka |
| 7 Sep 1978 |
the Constitution of the Democratic Socialist Republic of Sri Lanka came into operation |
| 7 Sep 1978 - |
Śrī Laṃkā Prajātāntrika Samājavādī Janarajaya (ශ්රී ලංකා ප්රජාතාන්ත්රික සමාජවාදී ජනරජය) = (from 14 Nov 1987) Ilaṅkai Caṉanāyaka Cocalicak Kuṭiyaracu (இலங்கை சனநாயக சோசலிசக் குடியரசு) | Democratic Socialist Republic of Sri Lanka |
| 14 Nov 1987 |
Tamil is recognized as an official language in accordance with an act passed by the Parliament of the Democratic Socialist Republic of Sri Lanka |
