The question asks for the specific date when the Muslim League announced its call for 'Direct Action'. This significant political move was a pivotal moment in the events leading up to the partition of India.
The Muslim League, under the leadership of Muhammad Ali Jinnah, called for 'Direct Action Day' to protest against the proposed federal structure of the Indian constitution and to assert their demand for a separate Muslim state (Pakistan). The intention was to mobilize Muslim support and demonstrate their resolve through both constitutional and unconstitutional means, though it unfortunately led to widespread communal violence.
The Muslim League officially announced the date for 'Direct Action Day' which was observed on 16th August, 1946. This date was chosen to show the League's determination and was widely publicized.
Therefore, the correct date announced by the Muslim League for 'Direct Action' was 16th August, 1946.