user: Question: Premier Sir Charles Cowper (1807-1875) KCMG left office 2 October 1856, when did he assume office?
Columns: ['Rank:', 'State:', 'Premier:', 'Party:', 'Assumed office:', 'Left office:', 'TOTAL Time in office:']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'SA', 'Sir Thomas Playford (1896–1981) GCMG', 'Liberal & Country League', '5 November 1938', '10 March 1965', '26years, 125days']
SQL:

assistant: SELECT "Assumed office:" FROM "Table" WHERE "Premier:" = 'Sir Charles Cowper (1807-1875) KCMG' AND "Left office:" = '2 October 1856';