Which one of the following statement is not correct ?

1. The National Song 'Vande Mataram' was composed by Bankimchandra Chatterji originally in Bengali.
2. The song 'Jana-gana-mana' composed originally in Bengali by Rabindra Nath Tagore was adopted in its Hindi version by the Constituent Assembly on 24th January, 1950 as the 'National Anthem' of India.
3. The 'National Calender' of India based on Saka era has its 1st Chaitra on 22nd March normally and 21st March in a leap year
4. The design of the National Flag of India was adopted by the constituent Assembly on 2nd July, 1947.