- The first session of the Constituent Assembly was held on December 9, 1946. - The Constitution was adopted by the Constituent Assembly on November 26, 1949. - The duration from December 9, 1946, to November 26, 1949, is calculated as 2 years, 11 months, and 17 or 18 days, depending on the calculation method (whether the start/end day is included). The figure 2 years, 11 months, 18 days is the widely accepted standard duration.